Fluidmaster 6000 Series AirGap Bottom Entry Height Adjustable Delayed Fill Valve. 1/2 Brass Shank, Bottom Entry, Eliminates Backflow, Faster Fixing, Fluidmaster AirGap Technology, Heavy Duty, Height Adjustment, High And Low Water Pressure, Saves up to 1 Litre of Water Per Flush, Spiral Vortex Generator. Compatible with BS1212. Ref: UTST10309