The PetSafe Spray Bark Collar is designed to help humanely and painlessly quiet your noisy pup. When your pup barks, the collar triggers a light burst of spray which can help to deter their noisy behavior. The collar has advanced bark-sensing technology that detects your pupfts unique sound and helps eliminate false corrections when other dogs make noise. The collar comes with two replaceable refill cartridges in unscented and citronella (try both to see which one works best for your dog). Each cartridge contains 35 sprays. The adjustable nylon collar is waterproof and lightweight. It fits canine companions 8 pounds and up and is adjustable for neck sizes up to 27 inches. The rechargeable collar quickly charges within 2 hours using a USB charger (included), has up to a 40-hour battery life along with low spray and low battery LED indicators. PetSafe has a inNo Bark Guaranteein.