6" in diameter. Fits #20 big blue whole house water housings with 6 ridges. Replaces the plastic SW-4 wrench Fits the following housing : American plumber W2010-PR / 152015/ W2015-PR / 152017 / 152022 / 144368, Pentek 150237 / 150239 /150469, Pentek BBFS-22, Pentek 144368, Ametek Kleen-Plus 144368, Culligan 144368, Big Blues, Keystone, Whirlpool WHKF-DWHBB, Axeon R.O. Systems, R1-6140, R2-6140, Axeon FSD Filtration Systems FSD-120, FSD- 220, FSD-320 Big APEC 20" and Compact 10" Blue, Clear, White, and Black Housings Made in the USA This listing is for 1 Superb Wrench SPBW-8 Heavy Duty Metal Water Filter Wrench 20in Big Blue Housings. For The Superb Wrench heavy duty metal water filter housing wrench replaces the plastic wrench that typically breaks when removing the filter housing unit. Made of heavy duty 7-gauge steel, the Superb Wrench will not break, bend or strip the housing unit. The handle is rubberized and longer than a standard filter wrench which gives you extra leverage, along with the word loosen and an arrow imprinted to ensure proper removal of the housing unit. Make filter changing easy, get your Superb Wrench today! Features: 6 in diameter. Fits #20 big blue whole house water housings with 6 ridges. Replaces the plastic SW-4 wrench Fits the following housing : American plumber W2010-PR / 152015/ W2015-PR / 152017 / 152022 / 144368, Pentek 150237 / 150239 /150469, Pentek BBFS-22, Pentek 144368, Ametek Kleen-Plus 144368, Culligan 144368, Big Blues, Keystone, Whirlpool WHKF-DWHBB, Axeon R.O. Systems, R1-6140, R2-6140, Axeon FSD Filtration Systems FSD-120, FSD- 220, FSD-320 Big APEC 20 and Compact 10 Blue, Clear, White, and Black Housings Made in the USA