Guide-on posts make it easy to load your boat onto your trailer and back your trailer down the ramp. They clamp to the rear of your I-beam trailer frame and extend out of the water, providing visual ... trailer frame with included I-beam clamps - no drilling required Adjusts out to 19" from trailer Made in the USA Specs: Quantity: 2 boat guide-ons Post height: 75" Note: Check with your state