This is the only LED bulb I was able to find that is Negative Post. It works great in old 6 Volt
lanterns that had incandescent bulb that was a yellowish light. I ordered the P13.5S rated at 4-12V and I'm very happy with the brightness of this bulb in the lantern. I use a 6V adapter in the lantern that allows the use of 4 D batteries in pace of a standard 6 V lantern battery.