Part No. 376 The 16 mm is Harkens smallest block. It is perfect for small synthetic control lines found on high-tech dinghies. The patented bearing system uses stainless steel balls in a captive grooved race and has a 250 lb (113 kg) maximum working load. Sheave (mm)16 mm Sheave (in)5/8 in Length (mm)29 mm Length (in)1 1/8 in Weight (g)11 g Weight (oz).38 oz Maximum line (mm)5 mm Maximum line (in)7/32 in Maximum working load (kg)113 kg Maximum working load (lb)250 lb Breaking load (kg)544 kg Breaking load (lb)1200 lb