C.E. Smith Roller Bunks 4'. Great for ramps where it is not practical to float the boat onto the trailer. Pre-assembled and pre-drilled for easy installation. Maybe be installed using mounting brackets if lift and/or angle is needed or may be bolted directly to trailer frame for a flat bottom boat or even mounted on top of existing bunk boards. Specifications for C.E. Smith 4' Roller Bunks: Manufacturer: C.E. Smith Color: Silver Features of C.E. Smith 4' Roller Bunks Durable 2" polypropylene rollers on 1/2" shafts mounted in a heavy gauge pre-galvanized channel Supports up to 1500lbs of well distributed weight Mounting hardware not included Sold in pairs Package Contents: C.E. Smith 4' Roller Bunks C.E. Smith 27700: Roller Bunks 4'