Some quick background: I have a '50 F1 that was my daily but got pretty smashed up on the highway a few years back. Been rebuilding it for a while and just got it back on the road. The gauges have always been nice but I had converted to 12v and just never got around to hooking them up properly. Enter the IVR. So I read that Ford – for whatever reason – used gauges designed for 6 volts well into the 70's and I think even early 80's. And the IVR (or instrument voltage regulator) is this fantastic piece of equipment that takes 12 volts and pulses it off and back on again through a set of points to average somewhere in the neighborhood of 5 or 6 volts. DONE. So I got one with the proper spade terminals, took great care in mounting it, wiring it, and proceeded to burn the (presumably) Chinese piece of junk out in the space of five minutes. Enter the solid state step-down regulator. And there it is. Also plastic. And VERY Chinese. I know for sure – it came straight from the country to my door. Much cheaper at around $7 to the IVR's 20-ish. But there has definitely been some thought put into this piece. The input can be anywhere from 3 to 40 volts, and output anywhere in that range. (Obviously you can't make more than what you put in) and the trickest thing is you have that dumb looking digital readout built right in! I actually laughed at the thought of that little display hidden under my dash but I'm here to say, I was able to wire it up and dial it in to 5.75 volts and my gauges have been ROCK SOLID for a few weeks now. Time will tell on the longevity but it's already outlasted the IVR by a mile. I bought a couple of them so I'd have a spare on hand but haven't needed it yet. The dash lights are all 12v in this pic. Only the gauges are running from the step-down.