I work on so many different types of engines from gas to glow I finally had to break down and spend the money for a good tach. I spent the $100.00 on a TNC and love it. I have a couple of the smaller cheap ones tossed under the bench that were total crap. Then I did a side by side test with my TNC and a buddys H-9 combo, was I ever impressed and surprised, they were both so close together I was in shock. Sense then I have done the same thing with several of those H-9 tach volt meter combos, anyone at the field I see with one I do the side by side test. I could have saved myself some money and gotten a new volt meter at the same time!! Very good unit. I haven't tried the small meter from H-9 but the Glowbee and the Tower/Hobbico for the most part are junk. I have found a couple that work but it's a rare thing. Good choice!!