This is the LX H20-RS1 2.0KW 1.5 inch heater With Thermoregulator.
Sensor compatibility: Sensor built in, the heater is controlled by a thermoregulator on the side of the module.
Material spec: Plastic
Required flow rate: Set by the pressure switch, this switch will need to be pressurised, if it runs straight to a big bore outlet with no bends, there will be no back pressure and it may not work. Pressure Switch Operated by an extra Cord.
Diameter: 50 mm
Between terminals: 120 mm
Overall length complete: 340 mm
High-limit thermal cutout built in. This unit is rated IPX5 and has CE approval.