The Kootenay HX is the most advanced knot passing pulley on the market. Aluminum side plates are used in conjunction with a high-strength aluminum sheave. Sealed ball bearings provide optimal efficiency and help to reduce the performance robbing resistance that is inherent in most multiple component systems. The primary carabiner hole accepts numerous rescue carabiners. Secondary carabiner holes are provided for use with tag or belay lines. Two quick-release pins may be used in order to “lock off” the sheave when a high strength tie-off is required.