MR 16. One 3 Watt LED. 2nd Generation metal heat sink. Up to 120 lumen output and only uses 3 watts of energy. Comparable to a 35-40 watt incandescent equivalent. Operates 12 Volts A.C. or 12 Volts D.C. This LED Light bulb measures 2.22in x 1.96in. CE and Rohs listed. Comparable to a 20 to 30 Watt incandescent light bulb. Long life up to 30,000 hours.