The Pulsar BPS holder houses 3 standard AA batteries and provides the perfect solution when your original ones become dead. Keep an extra battery case on hand as a preventative measure. The Pulsar BPS Battery Holder is constructed of rugged ABS plastic and works perfectly with Pulsar Quantum Thermal Monoculars, as well as Pulsar Forward DN55 Digital Night Vision. Pulsar BPS 3xAA Battery Holder PL79119