SmartTrack SKI Bayonet Pin Extended Houstin (ST3969)Smart Track Housings Bayonet Pin inserts in a hole drilled in the flat area of the rear deck in which the housing pin drops in and pivots to lock it in place. The Extended Tiller plate is measured from the leading edge of the blade housing to the center of the pin is 40mm. The Race & Ski housings are primarily for surf skis and race kayaks. The ski housings are the smallest of the SmartTrack rudder housings.