Superb Wrench SPBW-3 Heavy Duty Metal Water Filter Wrench (4.28 inch Inside Diameter) Inside Diameter: 4.28 in Fits: Universal Slim Line Housings, Flexeon - Axeon Double O Ring, LT Series, LT 200, LT 300, TF R.O. Systems, 4 Stage, 5 Stage, 6 Stage and Residential R.O. Systems Heavy duty 7-gauge zinc-plated steel Handle is rubberized and longer than a standard filter wrench which gives you extra leverage Made in the USA