The CMI 2 in. Service Line Pulley features:Strength: 7,500 lb. Sheave: Steel or AluminumMechanics: Bushing Sides: Aluminum Axle: Zinc Plated Steel Max Diameter: 12.5 mm/.5 in. Weight: 10oz/290g or 6.7oz/190g Color: Black or Red (Steel comes in Black; Aluminum comes in Red.)