Plier Ear Punch, Stainless Steel, 2 mm

I bought this for notching my mice's ears; as a breeder I need to be able to differentiate between them all for health monitoring reasons. This device caused unnecessary pain to my animals. I tried three times on different mice and all three times it failed to punch all the way through the ear. Now I have three mice with red, irritated ears and nothing to show for it. They'll all have to be redone once their ears heal (and when I can find a notcher that actually works). I guess I've got a $30 paperweight now.