The Fulton non-marring, marine grade all PVC trailer boat guide uprights are designed to allow for boat loading and launching to be quick and easy, and help prevent damage to your boat. It features high strength super gripper, bolt-on mounting brackets that attach firmly above or below the trailer frame to maximize mounting flexibility. It can be adjusted up to 16 In. on each side to ensure a custom fit to any boat hull design. For trailer frames up to 3 In. x 5 In. Made in USA. 50", White.