Charges 2 or 4 AA and/or AAA NiMH batteries at a time. Two green LED's indicate when batteries are charging. Reverse polarity protection prevents damage from incorrectly installed batteries. Charges NiMH batteries in 8 to 16 hrs, depending on type and number. Batteries must be charged in pairs. No shut-off mechanism, typical weight 5.9 oz. Fold-out plug. 120 V, 60 Hz. 57 mm W x 70 mm L x 132 mm H.