These boat trailer side guide boards help you load your boat quickly and easily. The guide ons help center your boat on your trailer making it quicker and easier to load your boat by yourself, especially in windy or strong current situations. This is a complete kit manufactured by Ce Smith / Shipshape. The kit includes everything you need to attach a pair of side guide boards to your trailer. This kit will fit trailer frames that are UP TO 3" wide and 4" tall. The bunk boards are 2" x 4" x 5' long and come pre-carpeted with marine grade carpet. The guide posts are made of 1 1/2" x 1 1/2" Pre-Galvanized Zinc tubing and measure 21" tall. The guide posts can be adjusted out 13" on each side and sit at a 75 degree angle. You can also mount the guide poles either above or below your trailer frame for extra height adjustment. This kit comes with everything pictured and includes every nut, bolt, screw and bracket that you will need to install them. All the mounting brackets are Pre-Galvanized Zinc, and the mounting u-bolts are Zinc plated and include nylon insert lock nuts.