This valve is designed for manual air venting of radiators. It can be operated using a screwdriver or a designated key. Please ensure you select the correct size; refer to the BSP standard sizing guide for assistance. Specifications: Size: 1/4" BSP (13mm external thread diameter) Maximum Working Temperature: +120°C Maximum Static Pressure: 1.0 MPa (10 bar) Weight: 0.0440924524 Pounds.