The Culligan(TM) CP5-BBS Level 4 Premium Filtration cartridge reduces sediment, rust, scale, dirt, coarse sand, sand, fine sand, extra fine sand and silt. The replacement cartridge fits the HD-950A. The filter is not recommended for use with non-treated well water supplies. The cartridge life is up to 6 months or 24,000 gallons. Cartridge change reminder sticker included.