C.E. Smith Aluminum PVC Post Guide-Ons - Visual markers when backing trailers down the ramp. Easily center you boat on your trailer when loading. Recommended for use with I-beam trailers in salt water. Features: Fits virtually any sized I-beam frame. 90 deg metal uprights allow for 19in of side adjustment 1-1/2in square aluminum uprights Patent pending upright corner bracket adds increased strength Can be mounted above or below the trailer frame 2-3/8in outer diameter white PVC tube Reflective caps offer enhanced visibility All mounting hardware included Sold as a pair