Key Finder Pair, Indisputably the Loudest, Long Life Replaceable Battery, High-Impact Polycarbonate Case, and Two-Year Warranty Loud, extremely durable, operates up to 300 feet, and battery lasts up to 18 months Includes two KeyRingers  either KeyRinger calls the other The KeyRingers are ready to use right out of the package - no setup or programming required Great for families  if you order multiple sets of KeyRingers, they can all be called simultaneously or individually Full 90 day, no-questions-asked, money-back guarantee and a totally free TWO-YEAR WARRANTY