Free 

This insert is mirrored from the original to maximize room for a wireless sensor (any) to remotely monitor humidity levels with one of any number of wireless sesnors integrated with your smarthome/IOT system. There are 4 heatset insert positions from which to choose to create a hard attachment point for your particular sensor (or use tape/velcro/whatever).
Link to the round sensors https://www.amazon.com/dp/B07GR67G1M
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