This boat trailer upright guide on kit comes with two Upright guides, manufactured out of 1 1/2 inch square Aluminum Tubing. The upright guides measure 46 inches tall with the legs measuring 24 1/2 inches long. The length of the leg allows for easy adjustments to fit your boat properly. This Kit also includes two PVC Sch. 40 poles and caps. The upright guides are designed to have the 2 inch PVC poles slide over top of it and rest on the tab already installed on the guide for the correct placement. The guides will typically attach into a cross member or by using u-bolts to attach to an I-beam frame. This Kit does not include mounting hardware. This Kit Will commonly mount on square tubing frames with a 1 1/2 inch Galvanized Boat Trailer Hat Bracket and by choosing the correct sized 3/8 inch Boat Trailer U-Bolts (sold separately). If you are using this method to mount this kit to your trailer. The correct measurements to take to determine the U-Bolt dimensions would be the width and height of your trailers frame. Keep in mind that you are able to user wider and longer U-Bolts that what your frame measures. Once the U-Bolts are tightened, your Aluminum Guide Poles will become snug inside the Hat Bracket.
For I-Beam Frames in most cases using (2) U-Bolts per side is adequate without using the 1 1/2 inch Hat Brackets. Very commonly on an Aluminum I Beam Boat Trailer Frame, using a Stainless Steel Square Ubolt 3/8 inch x1 9/16 inch x 2 1/2 inch U-Bolt gives you the correct width and length to pass through the I-Beam, or cross member. The Overall Height of this Guide Pole Set once mounted would be roughly 60 inches.
It is also recommended, especially if you are installing Boat Trailer Pipe Lights, to secure the PVC Poles to the Galvanized Guide Posts using a set screw or through bolt, to prevent the PVC from spinning and damaging the Trailer Lights.