The RC-3100  Pre-Tension pulley has been designed to work in conjunction with the range of RC Lowering Devices.

Simply attach a prusik to the main rigging line attach the pulley to the prusik place a couple of wraps around the lowering device then
loop up to the pulley; you now have a simple 3:1 ratio tensioning system which can easily be loaded, tensioned, and removed single handed.

RC3100 Pre-Tension Pulley