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.