MATERIAL: Metal, rubber. Outer thread: 1/4 inch. Safe and Stable: High-quality rubber is included, and the black non-slip rubber mat can effectively prevent the camera from loosening, helping to keep it tightened and protect your camera from scratches. QUICK TO INSTALL: The easy-to-turn handle on the screws allows for quick mounting to the camera's tripod mount. Secure: The screw thread allows for a tight and secure connection to your camera. Package Contents: 3 x 1/4\" digital camera mounting screws, fits most types of quick-release neck straps and attaches to the connector. Note: The data are all measured manually, please allow 1-3 cm error due to differences in light and screen, there may be some color differences, please refer to the actual item received.