Nikon MH-21 Replacement Battery Charger for EN-EL4 / EN-EL4a Batteries Quick charger for Nikon EN-EL4 and EN-EL4a batteries Charges lithium-ion batteries in roughly 100 minutes Ideal for photographers who don't have time to waste Measures 4.9 x 1.5 x 2.9 inches (W x H x D); weighs 8.8 ounces