ISC Medium Single Prussik-Aluminum Pulley has tamper-proof Rivets, in compliance with CE EN12278 (2007) & NFPA (1983). Rope diameter range: (mm)max 13mm (1/2") (MBS) Minimum Breaking Strength (kN): 50 (MBS) Minimum Breaking Strength (lbf): 11240 Wheel material: Aluminium Finish: Anodised Color: Red Weight (grams): 280 Weight (ounces): 9.9