Review on Non-Contact Handheld Digital Tachometer for Precise Measurements by Darrin Parasson

I stuck reflective foil on the flywheel of my 11 hp Kohler engine. tried different sizes and positions of reflective tape when I started the engine and TRYING to get a reading and WOW the numbers were everywhere, 300 800 150 400 900 etc. I got a better guess at RPM than it would appear, I would NOT recommend this product.