Review on BigTeddy 4-Inch French Cleat Picture Hangers Kit - Aluminum Z Bar Clips for Hanging Mirrors, Photos, Shelves, and Cabinets (4 Sets) by Sasha Hsiao

When attached to the wall and back of an object, they have absolutely no room to slip. In other words, they fit together too tightly and it takes a lot of force to lock them. REVISION: When assembling 2 parts when only connected to the object to be hung it was difficult, once I fixed the 2 parts to the wall they are quite simple and well connected. I have no problems with them and will use them again. I also had no problem with other comments about sharp edges etc., you work with tools. If a small sharp corner is a problem, perhaps power tools, screws, nails, etc. should be avoided.