Replacement filter for QCRO and QCUF Systems. Made in the USA. For maximum performance, replace filter every 6 months or 2000 gallons. Reduces sediment, rust, and dirt The RO-QC4-SDRF 4-Stage Sediment Quick Change Reverse Osmosis Water Filter Replacement by Tier1 is a replacement filter for the Tier1 RO-QC-450, QCRO, and QCUF systems. The ROQC4-SDRF is designed to reduce sediment, rust and dirt commonly found in drinking water. It's recommended that you replace the filter every 6 months or 2,000 gallons for a high-quality drinking water.