The 16 mm is Harkens 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 and has a 250 lb (113 kg) maximum working loadthe highest on the market compared to similarly sized blocks. The 467 and 484 use a narrow sheave for extremely small control lines and have a ferrule head for soft attachments. They use the same high load ball system. The 484 features a bronze sheave for added durability.