Fits 4×4 vinyl fence post .150 wall or less Actual dimension width 3 5/8 x 3 5/8 Designed to fit end corner or line post Comes with mounting hardware for concrete or wood deck: 4 3/8″x3Concrete Wedge Anchor 4 3/8″x3′ Hex Lag Screw 10 3/8Flat Washers 4 Screws with White Snap Cap Galvanized steel These galvanized steel towers are designed for installation of vinyl fencing only to concrete wood or other solid surfaces. Hardware is included for both concrete and wood mounting applications. Limitations: Posts: Blank Line Corner and End posts only. No 4-way Posts Rail: Rail size should not exceed 2wide or 8tall this is very uncommon Bottom Rail Gap: The gap between the bottom rail needs to be a minimum 1″.