This CNC machined plug and play adapter allows you to mount single or dual BMS WMI nozzles WITHOUT the expense and headache of removing and drilling your factory chargepipe. Shaves a ton of time off the Audi S4 WMI install and best of all is fully reversible. We suggest the BM10 nozzle for most S4/5 applications. Nozzles not included. Made in the USA.