The L4G24 has a breakaway feature that provides the wearer protection from neck or head injury. This NVG Mounting System is unique that it provides two modes of operation: The first allows the mount to break away from the base under a stressed condition, with this breakaway feature serious neck injuries and equipment damage can be minimized or avoided. The second allows the Universal NVG Mount to securely lock the mount to the base. Compatibility: This product is suitable for PVS15, PVS18, and GPNVG18 night view, note that PVS14 night view is not available! Material: ABS plastic, durable, wear resistant, lightweight comfortable. Easy to Use: Easy installation and one handed operation. Specification: Material: ABS Size Chart: 11cmx7cm/4.33inchx2.76inch Package Includes: 1 Piece NVG Helmet Mount Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful online shopping!