Pentair Com Port Expansion Module | 520818 Unions Reliable and accurate calcium hardness

Reliable and accurate calcium hardness testing results

bright appearance without causing damage to the vinyl material

Unlike traditional sanitizing systems

LED Efficiency: Reduces energy consumption significantly

Pentair Com Port Expansion Module | 520818 Unions Reliable and accurate calcium hardnessPentair Serial COM Port Expansion Board Kit (Adds RS 485 Communication Ports) 520818 The Pentair 520818 is a Serial COM Port Expansion Board kit used to add additional RS 485 communication ports to compatible Pentair pool spa automation systems. Its commonly installed when you need more connection points for equipment such as variable speed pumps, salt systems, heaters, or other RS 485 devices that communicate with the control panel. Key Features Adds