We offer competitively priced carbon block filters in standard size 10" x 2.5" and 20" x 2.5" plus Big Blue sizes of 10" x 4.5" and 20" x 4.5". Click on the wording below the picture of the size filters you would like to purchase and you will be transferred to the proper page. (click on "view all" to see all of the items in this category section)