Rola 59655 APE Series 42" Track Mount Kit Sheet Metal Removable Mount (51" Cross Bars) Adds a sliding cross bar system to bare roof vehicles and RV's Anodized aluminum cross bars, high strength molded nylon and stainless steel hardware for long life Anti-Theft features for peace of mind-lockable covers Lockable accessory channel for t-bolt applications Quick and easy installation and cross bar removal