Replacement option for all HotSpring, Limelight and Tiger River 1.0 or 4kw heaters. INCLUDES the needed pressure switch jumper; Titanium Element; Plug Adapter for Sensors for use on IQ2000 (1995-2002); 3/4" Inlet & Outlet Barb Fittings; Drain Tube External Kit; Auto Reset. Includes: AI #5-60-5009 / MFG #39204 Hi Limit; AI #5-60-5010 / MFG #39205 Temp Sensor. Serial numbers on models that use this heater: Aria AR 4H1001 2006-current; Envoy KK 1F1001 2004-current; Grandee GG 3G1001 mid 2005-current; Vista SS 1F1001 2004-current; Caspian CHP 3G1001 mid 2005-current.