Review on Mini Digital EMF Meter - Handheld Electromagnetic Field Detector with Backlit LCD, Sound & Light Alarm - Includes 2 Stickers - CAMWAY by Jack Duncan

4 stars overall for accuracy as I can't verify accuracy but the readings make sense. Remember that the inverse square law applies to EMF (look it up). A 40 V/m alarm means you are testing at a distance of 1 meter (39 inches). An alarm at 4 inches does not mean the exposure limit has been exceeded, it just means YOU are too close for safety reasons. Yes, microwave ovens leak, but not necessarily unsafe by today's standards. Even the lampshade of the LED lamp fires up to 6 inches. Understand what you are testing before leaving negative feedback. Obtaining an amateur radio license will benefit you.