Optimum Pool Technologies Replacement Flow Switch for Pentair IntelliChlor IC20 & IC40 Salt Cell - Replaces 520736 Replaces: Pentair Intellichlor Flow / Temp Switch (IC-20 & IC-40 Systems) 4 Wire connection Arrow on switch indications the direction of water flow, ensuring proper installation Manufactured by Optimum Pool Technologies Replaces Model Number 520736 IC15 IC20 IC40 IC60