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 and corrosion | C.E. Smith 60" Post Guide-On With I-Beam Mounting Kit in White