Extreme Max Heavy Duty Roller Guide On System. 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 corrode and deteriorate the finish. 6" bolt kit available for trailer frames up to 5" tall (Extreme Max 3005.4065). Features of Extreme Max 3005.3822 Heavy Duty Roller Guide On System Includes one pair of Heavy-Duty Roller Guide-Ons with an easy bolt-on installation that fits bunk or roller-style trailer frames up to 3" wide x 4.25" tall Custom-formed 97 arms and 13" roller assembly; up to 14" (3" trailer frame) or 16" (2" trailer frame) of horizontal adjustment Zinc-coated for freshwater corrosion-resistance not intended for use in saltwater or brackish water The size and shape of trailer frames can vary drastically please measure your boat on the trailer before ordering to ensure a proper fit 6" bolt kits are available for trailer frames up to 5" tall see Extreme Max 3005.4065 Package Contents: Extreme Max 3005.3822 Heavy Duty Roller Guide On System Extreme Max 3005.3822: Heavy Duty Roller Guide On System