This trap works, and works well.  I spread a little peanut butter on the inside floor of the trap and put it behind a basement door so the (useless) cats wouldn't frighten away the mice.  I caught two mice the first night and dumped them about a mile away from my house; they seemed unharmed  - one took off immediately upon opening but the other went back into the doorway and I had to shake him out before he'd leave.  They made quite a mess inside, so it had to be cleaned before I try to catch some more.  I'll be re-baiting it to see if I can catch any more.