This 1/4"-20 Flat Head Captive Camera Tie-Down Screw from SmallRig is useful to keep as a spare for your camera plate. The captive machined design helps the screw sit in your plate without a camera attached and not unscrew itself without having to tape it in place The knurled edge provides an improved grip when finger tightening, and the slot in the top of the screw accommodates a flat head screwdriver or coin for tightening or loosening.