Hydro Quip Universal Low Flow Rite-Fit Heater - 4.0kW. This Heater Replaces Many That Have Been Discontinued Or Are No Longer Available. 

Standard Features:
Titanium LWD Element, Heater “ON” Indicator Light, Hi-Limit Tripped Indicator Light, Built-In Manual Reset Hi-Limit, 3 Pressure Switch Taps, Reversible Foot Bracket, Adjustable Sensor Cover Kit, Replaceable Heater Element
Tailpiece 3” x 1”, 90 Degree Barb, Individually Packaged, And Installation Instructions.

Also Includes:
1” x 12” Tubing, Barb Adapter .75” x 1.0”, 60”, 3-Pin Amp Cord w/Terminals

This Heater Replaces The Following;
E2400-0115(ET), E2400-0015, E2400-0015ET, E2400-0001, E2400-0101(ET), ET2400-0201(ET), E2400-0021-NP, E2400-0021ET, E2400-0021, E2400-0021ET-1, E2400-0221, E2400-0127ET(X), E2400-1127ET, E2400-0126ET, E2400-0026, E2400-1127, E2400-0202-1, E2400-0204, E2400-0204ET, E2400-0203(ET), E2400-0007, E2400-0027, E2400-0351(ET), E2400-0012, E2400-0114(ET), ET2400-0014(ET), E2400-0028C, 20-00514, 26-00110, 26-00254, 26-00257,26-00155, 26-081214, 26-08145, 26-08146, 26-08159, 26-08157, 26-08114, 26-08115, 26-08102, 26-08108, 26-08118, 26-08119, 26-08109, 48-3300, 48-3600-40-003, 48-3600-40-014

Remember on any replacement you may need to do some re-plumbing     

If you're looking for a reliable and efficient hot tub control system, look no further than the Hydro Quip Universal Low Flow Vertical Heater - 4.0kW. This heater assembly is specifically designed to provide superior performance in Dimension One hot tubs, ensuring maximum reliability and efficiency. With its compact design and four-kilowatt power rating, this vertical heater assembly is able to deliver the desired temperature in a short span of time. Plus, its durable construction can withstand high levels of use without compromising performance. Experience unparalleled hot tub control with the Hydro Quip Universal Low Flow Vertical Heater - 4.0kW! Don't settle for anything less than the best when it comes to reliable and efficient hot tub control