40mm Carbo Single Ratchet Block with SwivelCarbo 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 A~ (mm): 40 mmSheave A~ (in): 1-9/16 inMaximum line A~ (mm): 10 mmMaximum line A~ (in): 3/8 inMaximum working load (kg): 136 kgMaximum working load (lb): 300 lb