The J2000 with tracks is an aerodynamically designed rack system that can fit any vehicle with or without drip rails. The unique shape of the crossbars minimizes wind noise. The A286 crossbars are reinforced aluminum with channels and can support 600 lbs. The mounting bases are 4in wide and 11-gauge high strength steel. This system includes 4 X 4in Side Support: Prevent material from sliding off the vehicle, 2 X Ladder Stopper: Prevent ladders from sliding forward (can be adjustable from 4in-6" in height), 2 X EZ Velcro Strap: Secures ladders in place within seconds. Aluminum Tracks allow easy adjustment or removal of rack system. Because the tracks can distribute weight more evening along the vehicle, the weight capacity increases as well.