My daughter is a world-renowned escape artist. She figured out how to pull these off our doorknobs the very day that I installed them, but because she gets her stubbornness from me, I wasn't going to relent. I put little pieces of packing tape on both seams and now they work wonderfully! They are easy for adults to use but are also great for keeping small children out of areas they shouldn't go. We have standard sized doorknobs and these fit just fine.