Greenlee 650 Hook Sheave, 4000-Pound Capacity, 6-Inch,Greenlee,650" /> 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 6-Inch, inside radius 1-1/2-Inch