Pet-Joint series Compression Type Fitting, by HKS, is based on the principle of convention compression method but elevates to a new height in which a smart engineered idea has been embraced into the locking system. The grooved pipe, silicone gasket, and screw nut work flawlessly together forming an airtight connection. Fittings comply with AS 3688 Section 6. Both 304 and 316 grades are available in size from 15 - 54mm with Hong Kong Water Supplies Department (WSD) General Acceptance (GA) approved.