It works as advertised. The device itself is very simple. I had a really clever mouse which has been dodging "Mice Cube" traps for sometime. It got caught in this. A couple of reasons for 4 stars instead of 5.1. There is no way to tell if there is a mouse inside or not. I had to shake the thing to feel the mouse inside. They should put a clear plastic atleast on one side to easily view.2. The design of the system is as such that if the mouse pushes or gets on top of the trap, it will trip without catching anything. So the mouse has to pass through the gate (see picture) for it to work. When I was setting it up, that's what I was afraid of. Fortunately the mouse did not get on top of it and got caught as expected.