6 Volt LED bulb operates in both positive ground and negative ground. Up to 320 Lumen output. This bulb is a single filament. Long life up to 30,000 hours.  Made with Samsung 5730 led chips. The BAY15S diameter is 15mm, has even bayonets and one contact on the bottom.  Up to 1 year warranty. Available in White 6000K. Size MOL from top to bottom is 1.47" and the diameter is 0.78". Uses only 2.6 Watts comparable to a 25 Watt incandescent bulb. . Order is shipped with two bulbs. The bulb starts to illuminate at 4.11 volts. The maxium bulb voltage is 18 volts. CE and Rohs