Fore & AFT Seat Slide Pedestal Mount - Fits 2-7/8" Post 
This seat slide pedestal mount has a 5-1/4" hole pattern and fits virtually all marine seat brands.
Features:
Cast aluminum mounting construction with injection-molded plastic handles
Extruded aluminum seat slide allows for 5" of fore and aft travel
360° rotation with a locking knob
Locks into pedestal posts with pre-tapped adjustment holes
Class AD certified per ABYC standards
Specifications:
Post Size: Fits a 2-7/8" diameter post