This kit includes an Under-body Coating Gun and a can of Dinitrol 3125HS (1L) , a specially formulated wax which penetrates rust and dirt preventing further corrosion. The Wax / Shutz Underbody Coating Gun simply screws onto a standard tin of under-body coating material and creates a venturi action that sucks up the material and pushes it through the gun nozzle. Comes complete with plastic spray nozzle and extension pipe for getting right into cavities or difficult to reach areas. This spray gun is designed to be fitted on to the Dinitrol Rust Treatment 1L cans with airline attached makes rust proofing your car easier - Or you can also use it with Schutz Underseal after welding the underside to keep the original looks as well as protect your car from the muck of the UK weather! 1/4 BSP Female Bayonet is available here . Not suitable to be used with the extension probe on the shutz gun as the product is too thick. *Not designed to fit directly onto CONVERUST RC800. You will have to decant into a shutz can with a screw top