40mm Carbo Single Ratchet Block with Swivel & BecketCarbo Ratchets allow sailors to hand-hold loaded lines and offer balance between holding power and controlled easing. 2608, 2609, and 2614 have on/off switches.Features:Sheave (mm): 40 mmSheave (in): 1-9/16 inMaximum line (mm): 10 mmMaximum line (in): 3/8 inMaximum working load (kg): 136 kgMaximum working load (lb): 300 lb Manufacturer : Harken Manufacturer Part No : 2609 UPC : 097653084105