This screw is a male 3/8 '' to female M6. Please confirm the screw thread specification you need before purchasing. This hand screw is mostly used for the installation of photography equipment, such as camera tripods, fill lights, selfie sticks, etc. The diameter of the nut part of this screw is 16mm, the height is 13mm, and there are intersecting textures on it to increase friction, allowing you to install and remove this screw without the need for a screwdriver. The material of this screw is aluminum alloy, which is sturdy and durable, and can replace damaged or lost screws. Package includes: 4x screws