The BP-1240 (aka the ON-THE-GO pack) is a 12-volt 4000mAh portable rechargeable Nickel Hydride battery pack. These are manufactured by BATTERIES AMERICA right here in the USA, using premium SANYO Ni-MH cells. Includes battery assembly, padded case w/ steel belt clip, DC socket, and wall re-charger. Battery pack size is approx. 4" x 4" x 2". Weight is approx. 2 1/2 lbs. Provides 12VDC power with 4Ah (4000mAh) LONG LIFE battery capacity. Wall recharger restores battery to full capacity overnight. This is the ideal soultion for 12-volt ON-THE-GO power requirements.