Quantity: you will receive 24 pieces 4mm x 15 mm threaded knurled thumbscrews, They are packaged in a small box for easy storage, making it more convenient for your daily use and replacement Material: they are made of quality carbon steel+ ABS, with good hardness, strength, corrosion resistance and wear resistance; It is a fastening accessory that can be applied for a long time and could be reusable for most different purposes Size: Thumb Screws Total height: 26 mm/0.82 inch; Head Diameter: 16mm/0.63in; the surface of the grip thumb screw on type round head is smooth, the thread is neat and uniform, without burrs, making the installation effect more tight Easy installation: the grip knob thumb screw adopts a screw-in design, Adopting a knob with an increased size of 16MM makes it more convenient for you to use,which is easy to install Warm notice: it is recommended that you need washers as gaskets when installing some monitors to prevent affect to the computer monitor; The length of the screw part is 15 mm, which may bottom out on some computer monitors; You just need a layer of buffer to prevent direct contact in some cases