PETZL Partner Pulley 4" high 4" wide CONSTRUCTION: The PARTNER pulley's aluminum sheave and sealed ball bearings ensure excellent efficiency. EASY TO USE: The swinging side plates offer quick and easy installation. COMPATIBILITY: This pulley is compatible with rope diameters of 7 to 11 mm. LIGHTWEIGHT: The PARTNER pulley is extremely lightweight, weighing in at only 56 grams. DETAILS: The PARTNER pulley has a working load of 5 kN (2.5 kN on one rope strand) and a breaking strength of 15 kN.