Best used as a replacement part for modern Necky, Old Town and Ocean Kayak brand boats, circa 2003-2004 to date. This part (part number 07.2694.0000) may be used for other brands of kayak. Base is 2 7/8 inches. Mounts onto a Flat Surface. Oval screw holes can accommodate spacing 1 ¾ to 2 3/8 inches. Ears stand 2 ¼ inches high. Multiple screw holes can accommodate bungee cord (with J-hooks). All plastic construction. Older Necky kayaks have curvature on the deck surface. Part number 07.2694.0000. Use the Rudder Rest Kit for older Necky kayaks circa 2002 and older. RUDREST