5" Adjustable 2-piece Post Socket facilitates a fast, easy and level installation of vinyl post sleeves to posts. These adjustable sockets fit a 2 3/8" OD steel pipe or sleeve using a 5" square posts and with a wall thickness of 0.150" or less. Each post in a fence system requires two post collars, each consisting of an inner and outer ring. • (2) Slip Mount post collars (2-3/8” pipe) • (4) Self tapping screws. #10-16 x 1” self tapping screws • Made from impact resistant 100% high density thermoplastic polymer.