The Harken 16mm Block is specially designed for small synthetic control lines, making it ideal for use on high-tech dinghies. It utilizes a patented bearing system with stainless steel balls in a captive grooved race, ensuring a maximum working load of 250 lb (113 kg). Additionally, the 404 model features an O-ring to keep the line securely in place during intermittent loading. This 16mm Block, Part No. 404, has a sheave Ø of 16mm (5/8 in) and can accommodate a maximum line Ø of 5mm (7/32 in). With its impressive capabilities and expert design, it is the perfect choice for any sailing enthusiast.