The Culligan® R50-BBSA Level 1 Basic Filtration cartridge reduces sediment, rust, scale, dirt and coarse sand. The replacement cartridge fits the HD-950A. The filter is recommended for use with city and well water supplies. The cartridge life is up to 6 months or 24,000 gallons. Cartridge change reminder sticker included. For Replacement Filter Use TV#'s 216911 & 852574.