Have added them to my business contacts.
Protects water supply from harmful chemical backflow - will not allow "spike" pressure to push chemicals into supply line.
Now required by many city and state regulations.
• Machined-Brass Housing, Chrome Plated Finish
• Plastic Diaphragm Check
• 3/4" Female Garden Hose Inlet (with Lock Screw)
• 3/4" Male Garden Hose Outlet
This part is listed as fitting the following models: