This boat trailer upright guide on kit comes with two Upright Galvanized guides, manufactured out of 1 1/2 inch square hot dipped galvanized steel tubing. The upright guides measure 48" inches tall with the legs measuring 24" 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 PVC pole slide over top of it. The guides will typically attach into a cross member or by using u-bolts to attach to an I-beam frame. Will also commonly mount on square tubing frames with 1 1/2 inch Galvanized Boat Trailer Hat Bracket and by choosing the correct size of U-Bolts. For I-Beam Frames in most cases using (2) U-Bolts per side is adequate without using the 1 1/2 inch Hat Brackets. The Overall Height of the Guide Pole Kit once PVC is installed will be roughly 52 inches. The Guide Poles in this kit are bent at 90 degrees for perfect alignment with the side of your boat. If you are wanting to mount this kit to a I-Beam trailer Frame or in the back of your trailers back cross beam, you can use either Galvanized Square Ubolt 3/8 inch x1 9/16 inch x 2 1/2 inch or Stainless Steel Square Ubolt 3/8 inch x1 9/16 inch x 2 1/2 inch. The width of these U-Bolts is perfect to go around the square tubing, and long enough to go through holes that you will drill. You will not need brackets in this circumstance.