Compatible with selected Elkay bottle filling stations and drinking fountains. Designed as a replacement for part number 51300C. Includes RFID chip for systems that require authentication. Replace every 3,000 gallons or 12 months depending on usage and water quality. Compact dimensions suitable for space-constrained installations. Please verify compatibility with your equipment model prior to purchase. This Filter is popular at schools, universities, gyms, churches, and hospitals and should be replaced every 6 to 12 months depending on usage.