CMI has been producing figure 8 rings since 1974 and since then has sold about half a million of these descending and rappelling devices. Indeed, CMI earned renown mainly because of the figure 8s. These continue to sell today but there are now two versions –the CMI Standard 8 Ring, which is the older design, and the CMI Rescue 8.

Like its predecessor, the CMI Rescue 8 is constructed of hot-forged 6061 T-6 aluminum alloy. This is aircraft-quality aluminum that is hot forged making the device strong and less likely to fracture. This is because the molecular alignment of the metal is improved with hot forging. The Rescue 8 is also much lighter than steel and produces excellent friction. For protection from rust and for extra durability, it is anodized with a hard coating.

The upper ring of the Rescue 8 is larger than the Standard version. This is intended to accommodate heavy-duty large ropes, even two of them. It has horns on its upper section preventing the sliding up and locking off of the rope. The tie-in end has dual holes keeping the descender attached to the harness during the threading of the rope to the carabiner. This prevents dropping of the device in extreme situations.

Ropes sized at 16 mm double, and from 12.6 to 19 mm single can be used with the CMI Rescue 8. It weighs 221 g and has a breaking strength of 10,000 lbs.

Originally intended for spelunking but eventually adopted by tree climbers and fire and rescue workers, the BMS Hyper Micro Rack is constructed of high-strength stainless steel tubes with heavy walls that resist corrosion and abrasion. In spite of the heavy walls, the overall weight of the rack remains light.

Although the racks of the BMS are approximately half the size of conventional racks, it offers increased strength. Its Frame Strength is rated at 14,000 lbs. Rating as Individually Tested is 1,000 lbs. load. Its Manner of Use Test is failure at 6,000 lbs. plus.

It has an extended top bar that is equipped with a pin, called the hyper-bar, that increases control options for descent. This is done by loping the rope around the bar. In addition to this, it also facilitates soft lock-offs.

BMS offers two lengths of their racks –one is 8 1/2 inches long while the other is 10 1/2. The former is intended for 3/8- and 7/16-inch ropes while the latter accommodates 7/16- and ½-inch ropes. Their width and thickness, however, are the same at 2 3/4 inches and 3/4 inch respectively.

Another variation is the second hyper-bar that is inverted below the upper hyper-bar. This provides an additional wrap for a more secure control of the loads carried by the rack. This system of having two hyper-bars helps squeeze the bar together when there is an increase in the input force.

The Petzl Pirana is a lightweight descending device primarily designed for a single rope. It may also be used with a double rope, but you may not be able to use certain braking positions with them, especially with large-diameter ropes. Petzl recommends 8 to 13 mm ropes for this figure-eight descender. Use of the Pirana is easy as it is not necessary to remove it from your harness for rope installation.

HMS locking carabiners with a cross section of 12 mm, such as Petzl Attache or William, work best with the Petzl Pirana. This is because such ‘biners fit snugly into the small attachment hole in the Pirana, thanks to a plastic attachment that grips them. In fact, the fit is so tight that you have to apply some pressure to get the carabiner in. This prevents them from getting accidentally loaded across the gate.

The Pirana features three braking positions. Your choice from among these depends on your weight, the diameter of your rope, and the terrain. Two supplementary braking spurs provide greater control over speed of descent by allowing the increase or decrease of friction. This allows a smooth descent even if you are carrying heavy packs.

The Petzl Reverso 3 is an ultra-light, multi-purpose, and easy to use rappel/belay device that can work well with ropes of different sizes for rappelling and belaying.

It features friction channels that are asymmetrically grooved in a V-shape. These allow the regulation of the breaking friction on the rope according to its diameter, flexibility, condition, and maneuver. The design also increases braking power in case of a fall or when rappelling.

When taking up slack, the rope also smoothly glides through the Reverso. The device is regarded as rope friendly as it does not kink ropes. It can be used for belaying with double as well as single ropes. It can quickly and effectively brake half and twin ropes with diameters of 7.5 mm or larger. For single ropes, braking is most effective with those with diameters of 8.9 mm or larger.

When mountain climbing on multi-pitch routes, the device can be used to belay seconding climbers in Reverso mode, but with the clipping of a carabiner into the carabiner hole, it can quickly change into a belaying device for the leader.

The Petzl Stop Descender is a belay and rappel device that was originally designed for caving where long descents on a single rope are common. It quickly caught the attention of climbers and it has since been used by all classes of climbers who need to get off the top of anything quickly, safely, and with a minimum of effort.

The Stop Descender incorporates internal cams around which the single rope runs. The rope from the top goes into the left side and around the bottom of the lower cam, then goes back upward to wrap the upper cam’s top, goes out to the right and drops towards the ground. A lever that is attached to the lower cam is on the left side.

If the handle is squeezed by your left hand, the rope is freed to feed into the cams. The speed of rope feed is controlled by the right. Varying your grip on it will either accelerate or slow the descent. If you need to stop, whether in an emergency or simply to rest, you only have to release the handle. This automatically brakes your descent.

Inserting the ropes into the Stop Descender does not require you to remove it from your harness. It has a spring clip allowing one side of the frame to pivot on an axle to expose the internal cams.

The Stop works with ropes with a diameter of from 9 to 12 millimeters. Dry, clean, and flexible ropes are most suited for this descender. Stiff and wet ropes may not be sufficiently gripped by the cams, thus endangering your descent.

The Mammut Smart Belay Device is designed to arrest an accidental fall of a climbing partner with ease. It is constructed in way that a small belayer can easily break the fall of a much heavier climber as it locks even with a minimum of force.

This inexpensive and lightweight tool features a locking device with a non-mechanical design that pinches even thin ropes to stop a climber’s fall. Its can work well with ropes from 8.9 to 10.5 millimeters. Lowering a climber is also easy as this can be accomplished by releasing the locking device through an extended lever.

Rope management is simple and straightforward. Feeding even an armload of slack into the belay device to belay a leader is quick and easy.

The Mammut Smart Belay Device is excellent for top rope and sport climbing. It can also be used for rappelling on a single line.

The Black Diamond ATC-Guide is both a belay and a rappel device. It has dual-friction capabilities, one a regular smooth friction side and the other a grooved side. This guarantees sufficient friction on the climbing rope to arrest the fall of a climber. For rappelling and lowering, the ATC-Guide has a small hole where you can attach a girth hitch for leverage to release it.

The Black Diamond ATC-Guide is made of hot-forged anodized 7075-TC aluminum which assures durability and strength. Ropes ranging for 7.7 to 11 mm are compatible with this belay/rappel device in a wide array of conditions.

Its variable friction design allows you to use different rope sizes for different conditions. When rappelling at high speeds or rapping with fuzzy 11 mm ropes, use low friction mode or LFM. On the other hand, when rapping with a haul bag or when working with thin ropes in wet conditions, use high friction mode or HFM.

The Guide Mode of the ATC-Guide allows the lowering of a climber who is much heavier than the belayer. It has a clip-in hole that is large enough to accommodate the sleeves of standard locking carabiners. It also has a double slot which allows the feeding of single or double ropes. A coated retainer wire keeps it in place.

Belaying and lowering a climber, whether from cliffs, walls, or trees, is made safe and simple with an Edelrid Eddy Belay Device. Threading it is straightforward as you only need to follow the logical flow of the rope. It is equipped with an emergency braking system that guarantees a safe descent even if the belayer momentarily loses concentration.

The Edelrid Eddy is made of four components –the body, cover plate, cam, and control lever.

The body and cover plate are made of anodized aluminum. They are approximately of the same thickness, and are joined by a 6.4 mm stainless steel rivet. The cam pivots on a stainless steel axle protruding from the body. From this axle, a button is pushed by a spring through a hole in the cover plate when closed. The attachment point, an 18 mm hole, is at to bottom of the body and cover. A cast steel anvil with a U-shaped groove sits next to the hole. This is where the rope runs over. This anvil and the lever assembly are held in position by a stainless steel rivet.

The cam is made of steel, having a webbed design and with reinforcing ribs. The right side has a V-shaped rope channel, while the left has grooves that provide a finger grip for rope feeding. The bottom has a flat area which squeezes the rope against the anvil if the cam rotates counter-clockwise as would happen in case of a fall.

The control lever is at the body and is attached to the cam by a link made of steel. When moved downward, the cam is opened. However, if pushed too far down, the cam closes. To open it again, you will need to raise the lever, but only up to a certain point, otherwise it will close again.

The DBI/SALA Fisk Descender is a simple yet effective descent control device. Constructed with 304 stainless steel, it is durable and corrosion-resistant. It is also smooth-flowing, with a good thermal capacity. This reduces increases in the temperature of the unit while it is rubbed against the rope during descent.

Looking like a modification of the rescue 8 descender, the Fisk features a large radius providing for a smooth descent. Its even surface helps minimize abrasions to the working line. Rope hockling and twisting is also minimized.

The Fisk Descender is often used for rappelling, work positioning, and rescue work. It is recommended, however, that a back-up fall protection gear be used in conjunction with this descender.

While the Fisk is designed to be used by a single person, it can carry a maximum working load of 440 pounds to allow for any gear or tool that is needed in climbing. In cases of emergency, two persons may be loaded as long as this is not tolerated for extended periods.

The Petzl Grigri is a self-braking belay device designed to help a belayer arrest the fall of a climber even if the latter is bigger and heavier than he or she is. It features a clutch that locks itself once it senses a sudden or abrupt and heavy load, much like a vehicle’s seat belt locks itself in the event of a collision or roll. Once a shock load coming from a fall is detected, the stainless steel cam within the aluminum side plates pivot to pinch the rope against the friction plate, also in stainless steel.

This belay device is suited to both top roping and lead climbing. It can also be used for rappelling on single ropes. With its reinforced nylon lever release handle to release the rope, it helps in a smooth and easy lowering of climbers.

Paying out rope is done with both hands, with the left holding the rope closer to the climber. The right hand feeds the rope into the Grigri while the left pulls it out giving the climber slack. Holding the free end of the rope stops a fall. This hold is also used for lowering and rappelling.

Petzl Grigri is intended to hold 10 to 11 mm diameter ropes. Those of smaller diameters run the risk of slipping through the cam and the friction plate thus allowing a fall.

This belay, weighing 225 grams, is available in blue, burgundy red, and gray.