This lightweight, full-strength, Prusik-minding pulley is ideal for mountain rescue, swiftwater rescue, or technical teams where equipment weight is a significant consideration. By machining the side plates, the thickness of the metal can be varied to maximize the strength-to-weight ratio, a process that cannot be done with traditional bent metal side plates. Sealed ball bearings provide high efficiency, and aluminum side plates protect the rope. An extremely low-profile stainless steel axle assembly reduces snagging on rocks, roots, and uneven surfaces. Designed for lifeline up to 1/2 inch (13mm) in diameter.