Made of heavy gauge?steel. Finished with the same durable, weather resistant black powder coating as the Front Runner Slimline II Roof Rack. Lockable. Uses small wire locks such as the Master Lock Luggage Lock model 4688D. Consists of two (2) brackets -? one to hold down the jack handle and the other to secure the base. Mounts easily to the side rails of the Front Runner Slimline II Roof Rack. Fits all size Hi-Lift Jacks. Note: This product is not compatible with Slimsport rack kit range.