This specially designed gun fits on to the Dinitrol rust treatment 1L cans with airline attached makes rust proofing your car easier! Can also be used to spray Schutz Underseal after welding the underside and give the original look as well as protect your car from the muck of the UK weather! The Wax / Shutz Gun comes with spray nozzle and extension pipe for getting right into cavities. 1/4 BSP Female Bayonet is available here . Not designed to fit directly onto CONVERUST RC800. You will have to decant into a shutz can with a screw top