Strong, welded steel frames | Forged steel closure-type hooks with 1-inch (25.4 Mm) opening | 5-Inch (127 mm) wide aluminum alloy sheaves with self-lubricating bearings | 4000-Pound maximum pulling capacity | Outside diameter 24-inch , inside radius 9-3/16-inchGreenlee's 4000-pound capacity hook sheaves are 5-inch (127 mm) wide aluminum alloy sheaves with self-lubricating bearings. Strong, welded steel frames. Forged steel closure-type hooks with 1-inch (25.4 Mm) opening. Select a sheave with a maximum rated capacity that meets or exceeds the cable puller's maximum pulling force.