Brand: Dorcy. MPN: 41-1644. The 40 Lumen 4.5V to 6V LED Replacement Bulb is the perfect way to upgrade your old flashlight. Operates with any 3 cell 4 cell or 6 volt lantern or flashlight. The bulb is a 10 year bulb and allows for 100 000 hours of use before any change is required. Forty lumens of light output provides greater value and visibility to older flashlights.