See here for a Bullet Headlight Trail Tech V2 Gauge holder. This besel holds the panel mount version digital gauge for Trail Tech's Tach-Hour, Volt, and Temperature Meter. This might also fit in other 60mm dash speedo holes as well.
It is a super snug, snap in, and tight fit. Could be hard to get out even, might have to pull lens out to be able to pop it out.
The V2 gauge is nice because it is also backlit if hooked up to a 12v power supply.