Hozelock 4mm Flow Control Valve Shuts off and controls the water flow in 4mm micro tube. Made from black and yellow UV stable material – quality feel, unrivaled performance and easy to see Use this product to control a flow of water along a 4mm supply line Full flow control – from Off to 100% flow High quality 4mm flow control valve. Made from UV stable plastic. Adjusts water flow Shuts off or regulates the flow in the 4mm supply tube