I bought this for the Sterling Engine and specifically for the rhombic drive. Luckily I have no interest in the LED light and voltage meter because I think they could do without both of these. The LEDs barely light up, and the voltmeter is so faint, it's illegible. Everything else is spectacular; just what I wanted. I'm a competent machinist, and I couldn't make this for the price I paid. I tried a few different fuels, even added a butane torch for a moment to see if I could get the voltmeter to show up better. It's best run with just 99% IPA and let it chug away. Super fun. Thanks, -Kevin