The 16mm is Harken's smallest block. It is perfect for small synthetic control lines found on high-tech dinghies. The patentened bearing system uses stainless stell balls in a captive grooved race and has a 250 lb (113kg) safe working load, the highest on the market compared to similarly sized blocks. Used for Dinghy control lines, Big Boat leach lines, Downhauls, Traveler controls, Spinnaker pole trip lines, Outhauls, Cunninghams, & Halyards on prams.