TRG's RappelMaster™ is used by many US SWAT Teams, Military units, and Rappel Masters.
It is made with 7075 Aluminum and is rated at 10,000 lbs. The design allows 9.5mm, 10mm, 10.5 mm and 11mm dynamic and static rope.
There are numerous friction settings for different weights and rappel speeds.
The RappelMaster™ allows one hand to control the rate of descent with no requirement for a break hand or for tying off when stopped.
There are 2 ways to stop. Squeeze the handle closed or let go!
Go as fast as you want and let go! You will stop!
It will not damage the rope!
In tests against all other devices, the results were that there was no other rappelling device that is safer or easier on your ropes.
Cirque Du Soleil has been using 20 units 3 times a for the past 10 years. They have had zero failures!