Float Valve High Pressure VF01 Part 1 Manufactured to BS1212 part 1 Plastic piston and seat - IMPORTANT NOTE, MOST PLUMBING PRODUCTS ARE STATED AS BSP IMPERIAL THREAD MEASUREMENT WHICH MEANS THAT ACTUAL DIAMETER OF THE THREAD SIZE IS APPROXIMATELY 1/4 INCH LARGER THAN THAT STATED IN BSP TERMS. FOR EXAMPLE THIS 3/4 INCH BSP THREAD ACTUALLY MEASURES APPROXIMATELY 1 INCH IN DIAMETER