16mm Triple Block with BecketThe 16 mm is Harken's 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.. Specifications:. Sheave: 16mm / 5/8in.. Length: 57mm / 2-1/4in.. Weight: 43g / 1.5oz. Maximum line: 5mm / 7/32in. Maximum working load: 318kg/ 700lb. Breaking load: 544kg / 1200lb