Part No. 396 High-strength pivoting lead blocks with cams are used for halyard controls on larger keelboats and as head knockers on dinghies and beachcats for sheeting directly from the boom. Hole spacing and rivet size are the same as Classic models, making upgrades easy. Cam reverses for either up or down cleating.Can be used as becket block. Footnote : Maximum working loads and breaking loads for blocks based on cam strengths. Sheave (mm)29 mm Sheave (in)1 1/8 in Length (mm)100 mm Length (in)3 15/16 in Weight (g)83.7 g Weight (oz)2.96 oz Maximum line (mm)6 mm Maximum line (in)1/4 in Maximum working load (kg)68 kg Maximum working load (lb)150 lb Breaking load (kg)295 kg Breaking load (lb)650 lb