The High Tech Pet B-3-Volt 1 Amp Battery 2-Pack for MS-4 ultrasonic transmitter collars powers a collar for approximately 2-months to 3-months. The Battery is designed for use only with MS-4 ultra-sonic collar which powers the High Tech Pet power pet electronic fully automatic pet door, the yard barrier and the sound barrier. The battery is lightweight, dependable and designed specially for the MS-4 and MS-5 Ultrasonic Collars and is guaranteed to avoid damage to the collar circuitry.