Rinnai REU-MSB-C1 Cable Connect for Rinnai Tankless Water Heaters For use with Rinnai tankless water heaters (except for models V53e, V53i and R63LSe which must use pressure activation valves, PVA) Temperature setting for connected water heaters is controlled by the temperature controller connected to the water heater with the Master MSB Board. Temperature controllers connected to the other units will provide maintenance codes for their respective units Used with the MSB-M kit to connect an additional water heater to the control board Includes cable B (9.8-Feet), brackets, ties, screws, and instructions