We've been using this set now for 6 months now and find it to be very sensitive and reliable. Set contains The sensor mat, base monitor (microphone), handheld monitor (speaker) and 2 mains adaptors for the base and handheld unit.
The sensor mat is an absolute godsend for new parents as you can get a good nights sleep knowing that an alarm will sound if no movement (breathing) is detected for 20 seconds.
Saw this offer instore at ASDA newton mearns on the end of aisle next to the self checkout tills (rrp£50 down to £10.64 - reduced to clear) and figure that it was a real bargain for anyone looking to get one either for their own wee one or as a gift for sleep deprived parents.
I realise it is probably store specific, but there were more than 10 units left when I was in so be quick and grab a bargain. If anyone else has seen this in asda anywhere else, just reply)