1. Easy to install, once installed, it will be firmly fixed. 2. The three kinds of screws can be combined to fit most projectors.(Φ6.35mm screw and Φ5.9mm/Φ3.9mm screw) 3. The thinnest M4 (ø3.9mm) screw is for mini projector camera, can not reach a load capacity of 5.5kg.Please be careful. 4. Suitable for small projectors, LCD or DLP projectors, digital cameras, camcorders, 35mm SLRs, etc.