BF090 Brass Elbows with female parallel threads to ISO 228 (formerley BS 2779) - 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