I bought this at the store and even though it serves it's purpose I found that it slightly slides on the carpet so I added Velcro strips not the fabric part for the carpet plays as that and it now locks into place..The second flaw hasn't been tested yet but I noticed the ball that holds the foot/base on might snap depending on the amount of force but that's not been tested and lets hope we don't have too.Yet over all it gives that added peace of mind.I gave it 4 stars based on these issues and because it sits a bit lose under the door nob. Even pressing it tight it seems to slip off the rim of the ring and grabs the neck of the knob...