USB geyser lamp

[Eben King]

Anyone know where to buy a USB geyser lamp?  I have one I bought a few years ago.  It still works.  The bulb is non-replaceable so I put some resistors in the USB cable to lower the voltage.  The light is dimmer and oranger, but it still bubbles.

Technically, it doesn't have to be USB.  One about 6" tall, no matter the power source, would be OK.  Thanks.