Self-Tapping Appliance Valve (also known as a self-piercing or self-cutting tap) It is designed to create a new water supply connection for appliances like washing machines or dishwashers by cutting directly into an existing 15mm copper pipe without needing to drain the system. 
Product Specifications
Manufacturer: Embrass.
Application: 15mm standard British copper pipe (unsuitable for plastic piping).
Output Thread: 3/4" BSP (standard for washing machine and dishwasher inlet hoses).
Material: Chrome-plated brass.
Features: Includes interchangeable hot (red) and cold (blue) indicators for easy identification. 
Typical Installation Steps
Clamp: Place the backplate/clamp around a clean section of the 15mm pipe.
Secure: Tighten the clamp screws evenly until secure, ensuring the rubber washer is correctly seated to prevent leaks.
Cut: With the tap in the "off" position, screw the tap body into the clamp. Turn it clockwise until the pipe is penetrated.
Secure Lock: Tighten the locking hexagonal nut towards the pipe to hold the tap in its final position (typically 90 degrees to the pipe).