3 x 10" Jumbo Cartridges: 5m Pleated Paper (for typical floating debri), 1m Meltblown (for mud & fine silts) 5m Coconut Carbon (for taste / odor / sprays) Always relubricate the sump orings and the sump threads; this enables hand tightening to achieve a seal, which reduces stretching & flattening of the sump orings. Sumps will gradually tighten due to the impact of pump pulsations. If your cartridge life is shorter than normal, why not save some freight? (the 6 pack fits into our standard courier carton)