The QD is an auto-locking rope controller that can be used for descending, lowering or locking off the TRACE 6.5mm aramid rope.  The QD is also designed to be a force limiter and will slip under a dynamic load that exceeds 4kN.  It is a core component in all TRACE systems and is used as part of the ascent, lower, haul and lead climbing capabilities that TRACE offers.  It should be stressed that this was specifically designed for use with the TRACE Systems rope and can only be bought as part of a system.