I wanted this device for peace of mind but since getting the device, the alarm goes off without reason, which is very unsettling for the time it takes to wake up and realise and check everything's ok. When I check my daughter, thankfully she's fine, and I can see no reasonable or obvious reason for why the device is not sitting close to her body. Another problem I find is the device does not turn on properly and I have to turn it off and then on again (sometimes twice) before it starts up the way it should. I returned the device to the manufacturer but they returned it saying there was nothing wrong. I don't believe them quite frankly, I use the device every day and I know when it's not working as it says in the instructions.
Despite the negativity I have written above, I would still recommend buying the device. I'd rather the device's alarm go off a million times unnecessarily than not at all.