Water Filter Opening Handle Ring Spanner Wrench for Big Blue & Big White Housings for 10" x 4.5" & 20" x 4.5" Water Filter Cartridges. An essential tool for your Big Blue or Big White Filter System. Suitable for Big Blue and other 20" x 4.5" and 10" x 4.5" Water Filter Housings for Whole of House Systems. Check Image for Dimensions and Profile of Filter Spanner. Suitable for unscrewing Filter Housings with four rib profile. Internal Diameter of Filter Spanner is 158 mm and the four lugs protrude out 4.5 mm.
