The Moov band is designed to be extremely comfortable, sturdy and flexible. Here are a few tips on how to keep your Moov core safely in the band:
Make sure the alignment knob on the Moov core is properly in the band hole.
Wear the band snug, but not too tight. You should be able to fit one finger between the band and your wrist.
Mount the core in the hole so the light shines through the holes.
The rubber mount should lay flat around the Moov core and not be folded over.