I really can't figure out why "worried mum" would shrill hysterically that we are not to trust this product. This product does exactly as it promises to do and as for the batteries not lasting long, that's simply not true.
When my son died of cot death at 6 months I was left with his twin and an understandable pathological fear that I would lose her too. (As a twin and having lost a sibling to cot death she was at an increased risk of sudden infant death.) I was a nervous wreck, standing over my daughter all the time, checking for breath with a mirror and generally half crazy with fear that she would go too. The Respisense gave me peace of mind. It meant I didn't have to constantly check on Emma because I knew she was ok, since the alarm wasn't sounding. It fits nice and snug to the nappy (although I found that rolling the top of the nappy over a few times to create a thick little lip was necessary)and I quickly found that I trusted it because it rarely went off. (The alarm I was using before consisted of wire taped to Emma's tummy, which were consistently coming off. The first time the alarm ever sounds your heart is absolutely in your mouth. When it is going off seven, eight, nine, ten times a night, you quickly become complacent, which is probably as unhealthy as being hysterical.
My daughter is a beautiful four year old now, but I still have the respisense in my drawer for when I have another child, as statistically I am more likely to lose another child to cot death having already lost one.