The PUR Plus RF-9999 Replacement Faucet Filters are a set of four blue carbon/charcoal filters designed for household use. Compatible with PUR faucet filters, each filter has a capacity of 100 gallons and is made of plastic material. The filtration method effectively removes impurities from the water, making it suitable for enhancing the taste and quality of tap water in the kitchen. Ideal for regular use, these filters are specifically designed for the PUR RF-9999 model, ensuring a perfect fit and optimal performance.