Extreme Max Heavy-Duty Roller Guide-Ons do more than help you get your boat on your trailer; they help stop a multitude of loading problems. They'll help you load faster and safer, keep you from loading too deep, keep your trailer position true and are especially helpful at night. They will fit bunk or roller-style trailers up to 3" wide x 4.25" tall*. These heavy-duty guide-ons feature custom-formed 97° arms with a 13" roller assembly and up to 14" (3" trailer frame) or 16" (2" trailer frame) of horizontal adjustment. Extreme Max Guide-Ons are zinc-coated and intended for freshwater use only. Use in saltwater or brackish water will damage the finish. *6" bolt kit available for trailer frames up to 5" tall (Extreme Max 3005.4065).