Description Details CMC Swivel Double Pulley - NFPA - Product Weight 4.6 oz (414 g) - Sheave Tread Size 1-1/2 x 1/2 in (38 x 13 mm) - Sheave Aluminum - Color Bronze / Slate - NFPA Rating General Use - 3 sigma MBS 44 kN (9,891 lbf)