This package includes the Nu-Clear Canister Filter Replacement Cartridge, 100 Micron, 18 sq. ft., for the Nu-Clear Canister Filter Model 522 along with 1.5 lbs of Inland Seas Premium Pelletized Activated Carbon (it fits in the middle of the cartridge), a Nu-Clear Canister Filter Replacement O-Ring, and Inland Seas Super Lube Silicone Lube, 1cc.

Carbon should be replaced in aquariums every one to two months. O-rings should be replaced once a year. Every time the 100 Micron Nu-Clear Canister Filter is cleaned, when putting the lid of the Filter back on you should lubricate the O-Ring with Inland Seas Super Lube Silicone Lube, 1cc.

Cartridge dimensions: 8.5" wide and 8 3/8" tall. Center hole is 4" wide.