RWO's long established range of strong reliable stainless steel rudder hardware is constructed to the highest standard and electro polished. As a guide for usage 6mm. (1/4) pins are suitable for boats up to 3m (10ft), 8mm pins (5/16) for up to 3.5m (12ft) dinghies and 9.5mm 3/8 up to 6.6m (22ft) dayboats. Also to be taken into consideration are many other factors such as the boat's displacement, rudder size and transom, depth etc. if in doubt check out the design. Retaining clips spring rests on rudder or Transom gudgeon to prevent release of rudderhead. Rudder pins offer extra strength. to fit 8mm (5/16) gudgeon.