ITEM NAME:Water Purifier Reverse Osmosis Tee Inlet Ball Valve Set 1/2" BSP To 1/4" Tube x1.They usually use for water filtration system or RO reverse osmosis system. 1/2" BSP male usually for your tap hose. 1/2" BSP female usually to your male water pipe from the wall. And inlet ball valve to connect your 1/2" male thread piping (usually off the wall) to the 1/4" (6mm) tubing for water filter system or RO system and to your kitchen tap hose.