This Hitch Pin or R Clip Split pin is made specifically for the Smart Track Rudders. The Rudder Tension knob holds the rudder blade into the blade housing and also tensions the rudder spring. This Hitch clip is used to stop the tension knob falling out. This Pin but does fit some other brands including the Surge Rudders (that use split pins) It is a slightly heavier duty than the supplied Surge but fits easily. Stainless Steel Hitch Pins have a number of other non kayaking uses so might be handy if you need a rust resistant version for around the house.. Made of Stainless Steel MPN: 44-505
