Petsafe Nano Bark Collar - PBC00-10782 + Free Battery ($14.99 Value) Nano Technology - the smallest bark collar available. Weighing only 2 oz. -Collar adjustable for neck sizes up to 16" -Recommended for pets up to 55 lbs Patented Perfect Bark detection technology ensures your dog's bark is the only sound that will cause the correction Temperament Learning automatic correction level adjustment -Ten levels of Light-Touch correction Durable, Waterproof Receiver Collar - QuickFit buckle provides a quick release and a perfect fit every time Two-color LED for good/low battery indicators -On/Off position for longer battery life - Uses a PetSafe RFA-188 battery -Lifetime Limited Warranty