The Balboa BF900FL Commercial BetterFilter is a 900-sq ft cluster cartridge. 

Harmsco® Betterfilters® are for Commercial and Public Pools and provide sparkling clean water and save energy and space. Betterfilters® are constructed of low carbon T-316 stainless steel, electro-chemically polished to deliver a ten-year, pro-rated warranty. Harmsco® filters install quickly and easily, require no costly waste disposal systems, and come ready for use with Harmsco’s reusable SuperTuf/6TM Polyester-plus cartridges for maximum operating performance and a long service life.

http://harmsco.com/media/pdf/SP%20Betterfilters.pdf

Manufacturer: Harmsco CLUSTER W/ 150 SUPERTUF CARTR 4" MPT HARMSCO Dimensions:  28 x 28 x 76  inches Weight:  291 pounds