We purchased this unit when we had our first baby.
I was sceptical as to whether it would be sensitive enough to work through a mattress.
I can confirm that the sensors do work as a child stop breathing on us twice and the unit picked it up each time.
Turns out our child has central Sleep problem which this unit help pick up.
Highly recommended to anyone having a child just for piece of mine.
So good I have purchased 3 others for the mother in-law and the wife's sister.
purchased as present for son posted direct to his address item arrived in another product box altered with texta? as present did not look good can only assume is new product.