Wilesco Z02B Compressed Air Boiler Adapter for Pull Chain type whistleUse this Nickle plated fitting to run your Wilesco steam engine on compressed air and still use your whistle with safety valve protection. This fitting is for boilers that use the Pull Chain type whistle D 12, D15, D 16, D 18, D 20, D 21, D 22, D 24, T 90. Fits all newer engines from 1990 on. This valve will NOT fit earlier engines. Does not come with whistle. Click on picture for large view.