Large diameter sheave mounted on sealed ball bearings delivers 95% efficiency. Accepts up to three carabiners to facilitate use. For use with rope diameters from 7 mm to 13 mm. * Working load: 4 kN x 2 = 8 kN. Breaking load: 36kN. Sheave diameter: 38 mm. * Certifications: CE EN 12278 and NFPA 1983 General Use.