The Hydro-Quip ECO2 and ECO3 temperature sensor is designed for compatible systems built after May 2003 where the correct 4-pin temperature sensor is required. A temperature sensor is useful because it provides the control system with the information needed to manage heating and temperature-related operation accurately.This version is especially useful for supported post-5/03 systems requiring the B4-style application, a 3/8 inch diameter probe, and a 10 foot sensor lead. Matching those specifics helps keep the replacement aligned with the intended control pack design.The 34-0203D is a practical service part when a compatible Hydro-Quip system needs a correct ECO2 or ECO3 temperature sensor to restore accurate monitoring. Hydro-Quip ECO2 and ECO3 temperature sensor Designed for compatible systems after May 2003 10 foot lead, 3/8 inch diameter probe 4-pin connection format Supports dependable temperature monitoring