Roller Pontoon Guide-OnIdeal for bunk style pontoon boat trailer with box, channel, or I-beam frames up to 3″ wide x 4-1/4″ tall. Minimum friction rolling action easily guide pontoon boat onto trailer. Height is 25″ above trailer frame. Mount with roller bunks 2-3″ from pontoons on a trailer fram cross member. Features:Fits frames up to 3″ wide x 4-1/4″ tallU-bolt mounting bracketsIncludes two rubber roller bunksGalvanized steel constructionZinc plated hardwareFor larger trailer frames check out the Large Frame U-Bolt Kit (11416).WARNING: This product can expose you to chemicals including ARSENIC ,CADMIUM which are known to the State of California to cause cancer or other reproductive harm, and BERYLLIUM,COBALT METAL POWDER,NICKEL (METALLIC) which are known to the State of California to cause cancer, and Chromium (hexavalent compounds),LEAD which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.