This one-piece panel bracket, braces your keel roller on your trailer, for ease of launching and loading your boat. Don&';t make boating a hassle, get the Tie Down Hull Sav&';r. Success is right in the name! Bracket Height: 3-1/4" Base Width: 10-3/8" Base Length: 7" Slot: 5-17/32" One piece Heavy-duty hot dip galvanized 11 gauge steel Supports keel rollers Provides vertical roller adjustment Slots accept 7/16" or 1/2" diameter bolts Use 1/2" or 5/8" rollers