[gearhead1952]

I bought some 12V ones for my trailer. LEDs operate on a very low voltage, a lot less than 6v. So a dropping resistor is mounted in the assembly somewhere. I can easily see the resistor on the bulbs I got. Simple matter of soldering a replacement resistor in there to work on 6V. I agree the SMDs are the ones you want. The resistor size will depend on how many leds are mounted on the assembly.