The 16 mm is 's smallest block. The patented bearing system uses stainless steel balls in a captive grooved race. We strive to provide new innovative products to meet the need of the rapidly changing world we live in. Our goal is to provide products made with the finest material and consistent and high quality processes. Specifications Sheave: 16mm Length: 54mm Maximum line: 5mm Maximum working load: 204kg Breaking load: 544kg Weight: 0.1 lbs