Cash Acme Heatguard Tank Booster Thermostatic Mixing Valve - Enhances Hot Water Output While Preventing Scalding & Potential Spread Of Legionnaires' Disease - Allows Water To Be Stored At 140F Or Higher While Distributing Water At A Safe 120F - Hot Water Output Increased By Up To 50% Due To Higher Storage Temperatures - Compatible With Both Electric And Gas Water Heaters - Easily Connects To Existing Water Connections On Water Heater - Ideal For Hydronic Heating Applications Too - Easy To Adjust Dial Ensures Ideal Temperature For Outgoing Hot Water - Outlet Temperature Range From 90 - 130F With Factory Set To 120F - ASSE & CSA Certified - Mfg #24832