Bearing Checker makes a proactive approach to maintenance economically feasible for everyone. It is a useful and low cost complement to your maintenance toolbox. Without specialised training, users can detect potential problems well before damage is detectable by heat and vibration.This unique three-in-one device uses shock-pulse technology along with built in temperature measurement and electronic stethoscope function (headphones sold separately) This can give you an indication of bearing or lubrication problems. Measures shock pulse for early detection of bearing and marginal lubrication conditions. Electronic stethoscope function detects sound irregularities. Simple to use with 'traffic light' indication LED green (okay) - yellow (alert) - red immediate action required.