The design is great. The action is quick. The main problem is you must use it in warm temps. When the band gets cold, it will not push the band off. If it does come off the rat can wear it as a necklace, and they just push it off. If the band worked as good in cold weather as it does in warm weather, I would give it five stars.
Looks like a great idea, but nothing's been caught (though I've caught rats in my T-Rex traps). The rats in my neighborhood are so big I'm not sure how they'd get their neck down that little clear area, and I suspect they're too smart to stick their heads in there anyhow.