AquaCera LP-5 Gravity System w/ 2 CeraGravPlus Filters 0.9 Micron absolute - 100% removal of cysts - 99.99% pathogenic bacteria Chlorine reduction 95% - Organics reduction 95% Cleanable for prolonged life - Silver-impregnated to prevent bacteria growth Comes with 2 2" by 7" CeraGrav Filter Elements - Cerasyl ceramic outer shell-coconut GAC core The holes which are not in use are filled with removable rubber plugs (provided) for versatility