The C.E. Smith 60" Post Guide-Ons allow you to see the location of your trailer when it's under water. Designed for I-beam trailers and I-beam boat lifts, these guide-ons feature an innovative two-piece mounting clamp that works above or below the I-beam. Brackets will fit onto any height and virtually any width I-beam trailer frame.•Mounting hardware included•Adjusts out to 19" each side•1-1/2" square. 16 gauge pre-galvanized steel uprights•2-3/8" diameter white PVC posts•Pre-galvanized steel parts are stamped from a sheet of steel after it has already been galvanized•The galvanized coating is very thin (0.45 oz. on each side) Comes with mounting hardware for easy install Galvanized parts resist rust & corrosion | CE Smith C.E. Smith 60" Post Guide-On With I-Beam Mounting Kit in White