SIDS monitor

Was reading a blog about what to buy for the baby (FTM) and came across this ... It's a monitor for SIDS, and it sets of an alarm if they don't breathe within a certain amount of time and vibrates if they don't breathe for 15 seconds. It attaches to their nappy. I never even knew this existed! I am totally going to invest in this, it's always been a worry for me and I think I will sleep more soundly knowing that I have this little device.  Anyone have this or thinking of getting this?