This part secures the base of the CSS seat back assembly found on Wilderness Systems Tarpon, and the Perception Pescador, both circa 2002-2009 as well as some models of the Perception Tribe series. Also for Perception Search and some Wilderness Systems Ride sit-on-top kayaks. (CSS Comfort Seating System)
If you are replacing a damaged seat clip you can re-use the original mounting hardware (Screw) it should screw straight into the inset brass thread in the kayak deck. Otherwise it may require a new screw (Stainless Steel imperial)
Clip is 2.5 x 5.5cm (1 x 2.25 inches), just over 2.5cm (1 inch high). The diameter of the semi-circle opening is 2.2cm (7/8 of an inch).