This Bark Collar uses Nano Technology – making it the smallest Bark Collar available! Patented Perfect Bark detection ensures your dog’s bark is the only sound that will cause the correction. The PetSafe Little Dog Anti Bark Collar has ten levels of correction along with a durable, waterproof receiver collar. This anti bark collar features two color LED for good/low battery indication. Includes the RFA-188 battery module, and operating guide. Anti bark collars are a safe, humane and effective way to stop excessive barking. PetSafe anti bark collar is the best way to control nuisance barking. Get more information on this Bark Collar.