Go Rhino RB20 Slim Line Running Boards with Brackets Kit Model 69443580STGo Rhino RB20 Slim Line Running Boards with Brackets Kit Model 69443580ST The RB20 Slim Line Running Boards offer the same heavy duty toughness as the original RB Series, but with a slimmer design that fits tighter along the cab for increased ground clearance when off roading. Constructed from 16 gauge zinc coated galvanized steel, the Raptor inspired boards were built to protect your panels from flying debris while providing a full length step