The Harken 57mm Ratchamatic HTE Block Swivel, with Part No. 2625.HTE, has a sheave Ø of 57 mm (or 2 1/4 in), a maximum line Ø of 10 mm (or 3/8 in), and a maximum working load of 227 kg (or 500 lb). This innovative block features load-sensing technology that allows it to roll freely in both directions under low loads, while automatically engaging the ratchet as loads increase. The high-threshold engage (HTE) version of the 57 mm Carbo Ratchamatic blocks has a stiffer spring, delaying the point where the ratchet engages and allowing for a smoother experience. With a medium/light air grip and a 10:1 holding power, this block is perfect for crisp gybes and improved performance.