2.5 Volt 0.25 Watt Incandescent Bulbs Clear Bulbs With A Green Style D Base Check Pictures For A Base Measurement Diagram Indoor/Outdoor Energy Saving Bulbs Usually Used In 200 Light Strings One Or More Can Burn Out And The Others Stay Lit 20x 2.5 Volt 0.25 watt Energy Saving clear glass with green style D base mini incandescent bulbs. 20 New replacement bulbs. This is the style where one or more can burn out but the others stay on. You can also remove these bulbs from their base to use a different style or color of base. Standard mini bulb with rounded end, base measures: 0.45" Long overall, 0.36" insertion depth, 0.27" wide on inserted part of base. Check the base measurement diagram in the pictures. Make sure these bulbs are the correct voltage and wattage, using the incorrect bulbs will cause them to be dim or burn out very quickly. These 0.25 watt bulbs are usually used in 200 light strings, and using them in a smaller string will cause them to burn out very quickly, be sure you need the 0.25 watt bulbs. I have other colors and styles listed.