Fireboy Relay Control Module 669-RCM5
The old CMD-4M-RLY requires two parts to replace it - the CMD5-MDI Interconnect CO Alarm and the RCM5 Relay Control Module.
If your CO Alarms are interconnected and you do NOT have generator shutdown, you can use just the CMD5-MDI units and interconnect them.
If your boat is equipped with generator shutdown you need the RCM5.
![](https://cdn11.bigcommerce.com/s-ztr3z4ue/images/stencil/100x111/products/10901/12262/4833040__93088.1690203690.jpg?c=2)