High Tech Pet Micro Sonic 5 Water-Resistant Collar with Digital Transmitter MS-5 Operates all High Tech Pet Power Pet electronic pet doors as well as Sound Barrier and Yard Barrier sonic fences Using all digital circuitry, this state of the art design provides a stronger signal and maintains better accuracy over all temperature ranges With a fully enclosed ultrasonic speaker, the MS-5 is waterproof and rugged Immiscible in water; stands up to heavy rain showers and is perfect for dogs who love to play in the snow One size fits all dogs and cats; includes an attractive, tough 27 inch nylon strap