Its a digital gauge that you can tell water psi, temp, rpm, trim, gallon used and all that fun stuff. Its the only way to to with a Merc.
Pretty sure you can get these type gauges for about any brand, I know for sure Yamaha.
Well when I say I know they make them for Yamaha it was because I have seen the ones like this.. http://www.amazon.com/Yamaha-Outboard-Multi-Function-Tachometer-6Y5-8350T-83-00/dp/B005CXL1UI