Fibaro FGK-10x - Potential free/dry contact input?

Hi All

Is anyone using these? I have a front gate which has no means to detect state. I was considering just using the main part and not using the magnet, then connecting an outdoor/IP rated contact sensor plugged into it for my gate. I could put the ZWave body inside the letterbox to keep it from the weather.

I need battery powered so I figured this was about as good as I could find here in Australia.

Been keen to see if anyone is using these for external contact sensors