Extreme Max 3005.2196 2' Bunk Trailer Guide-On Includes one pair of 2 bunk-style trailer guide-ons Heavy-duty, corrosion-resistant construction and hardware specifically designed for marine use Easy, bolt-on installation fits bunk or roller-style trailer frames up to 3" wide x 4.25" tall* The size and shape of trailer frames can vary drastically, please measure your boat on the trailer before ordering to ensure a proper fit (see Image #2 for guide-on dimensions and measurements) * 7" bolt kits are available for trailer frames up to 5.5" tall, see Extreme Max 3005.4050