Any experience with the "Tiny Tach" diesel Tachometer?

[Hendo]

Interesting concept; a sensor that clamps around one of the injector fuel feed lines senses the fuel pulses and uses that to determine engine speed.

http://tinytach.com/diesel.php

I'm not to fond of the digital display, but at $95 I like the price, and installation seems easy enough.

I was just wondering if anybody here had seen one of these in action.

-Tom in SoCal