Charges 2 or 4 AA and/or AAA NiMH batteries at a time. Two green LEDs indicate when batteries are charging. Reverse polarity protection prevents damage from incorrectly installed batteries. Charges NiMH batteries in 8 to 16 hours, depending on type and number. Batteries must be charged in pairs. No shutoff mechanism, typical weight 5.9 oz Fold-out plug. 120 volt, 60 Hz. 57 mm width x 70 mm length x 132 mm height.