Fits all Pac Bay A5, A6, A8 & all #16 graphite reel seats. Fits all American Tackle 3UL reel seats. Threaded aluminum insert with rubber O-Ring, cork body and black rubber. Includes an aluminum mounting plug and a removable fighting butt. Mount as up or down locking for all-aluminum reel seats. Uplocking only for aluminum/Dynawood reel seats.