Ben Wilson Surf Depower Restriction ball
This ball is located at the end of the depower line which runs through the clamcleat. It ensures that the trim line can never shoot through the trim cleat, so you can always control your power. The ball slides easily over the line, with an Allen key (FCS) you can adjust the ball and secure it at the right position.
This ball is a very handy tool on other bars from different brands. You can buy a piece of depower line, make it the right size and put this ball at the end. This way you keep a good grip, you can easily depower it and you don't have to worry that your line will shoot through the clamcleat. You can do this with the bars from Naish, North, Slingshot and other brands that use a rope depower line.
The Depower restriction ball is also used on the BWS leash.