The Microsonic 2 Plus ultrasonic transmitter collar is ideal for your self-sufficient modern pet. This lightweight collar fits most cats and dogs comfortably. Emitting a directional ultrasonic code, the collar automatically works with all High Tech Pet ultrasonic pet-controlled products, including all Power Pet electronic pet door models, Sound Barrier indoor sonic dog and cat fence and Yard Barrier outdoor sonic dog and cat fence. The collar\’s rugged and water-resistant build helps prevent damage. One lithium battery is included and typically lasts around 4-month. Replacement battery is High Tech Pet model B-2430.