PETZL Ultra Legere Pulley Wheel INTENDED USE: The ULTRALEGERE can be installed on a carabiner for emergency use. LIGHTWEIGHT: The size and weight of this pulley are reduced to an absolute minimum, making the ULTRALEGERE the lightest pulley available at only 10 grams. COMPATIBILITY: The ULTRALEGERE pulley is designed for use with a symmetrically shaped carabiner. DESIGN: The ULTRALEGERE is a simple nylon sheave that accepts ropes 7 to 13 mm in diameter. DETAILS: This pulley has a working load of 1 kN.