Car Spark Plugs Engine Digital Tach Meter, Motorcycle Electronic Tachometer with Digital Display Timer Gauge, for Small Gasoline Engines, Chainsaw Marine ATV Motorcycle UTV Engine (Black, with Clip)

Definitely works good for what you pay! On the higher rpm side on chainsaws it def has a slight lag and a couple hundred rpm off give or take. But can be expected from anything you buy in the "budget category " if your looking for dead nuts accuracy then go spend 100$+. If your looking for a cheap meter to tune your chainsaw a few times as a do it yourselfer then buy this!

Did it stopped working yes

Worked well, used it to adjust rpm on my Polaris Sportsman. Wire with clamp is not necessary as it will pick up current just by putting unit close to spark plug.