Tie Down 86121 Boat Trailer Adjustable Keel Roller Bracket Assembly The Tie Down Trailer Keel Roller Assembly Kit features adjustable offset brackets that mount on the trailer tongue for keel support. This assembly comes complete with a 4 rubber roller for 2 wide tongue and hardware as shown. Brackets are hot dipped galvanized for lasting protection. Assembly Includes Adjustable brackets 4 Rubber roller 2 Zinc plated hex bolts 2 Zinc plated nyloc nuts Hardware is for mounting onto 2 wide trailer