4 x 10" Jumbo Cartridges: First stage 1 Micron Meltblown, Second stage 5 Micron Carbon, Third stage 5 Micron Carbon, Final stage 1 Micron Meltblown 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.