Compact double pulley for block-and-tackle systems. Main attachment point accommodates two carabiners and the becket features a bottom attachment point for linking components in a block-and-tackle system. For use with ropes up to 1/2 in. Prusik minding, the self-locking knot can be installed on both sides of both wheels. Self-lubricated brass bushings are sufficient for light applications at low speed. Efficiency: 80%. Aluminum alloy body and wheels, stainless steel axle.