These post guide-ons allow you to see the location of your trailer when it's underwater. The 2" PVC tubes also make it easy to note your trailer's position when backing down the ramp. Designed to fit frames up to 3"W x 4-1/4"H. Guide-ons adjust out 13" on each side. Stand 40" above the trailer frame. 2-3/8" O.D. Mounting hardware included.