The 16 mm is Harken's® smallest block. It is perfect for small synthetic control lines found on high-tech dinghies. 404 block uses an O-ring to keep the line in the sheave during intermittent loading. The patented bearing system uses stainless steel balls in a captive grooved race and has a 250 lb (113 kg) safe working load - the highest on the market compared to similarly sized blocks.
Use for: Dinghy control lines, Big Boat leech lines, Downhauls, Traveler controls, Spinnaker pole trip lines, Outhauls, Cunninghams, Halyards on prams.