This little meter is great and works just as well as some of the more popular and more expensive meters and its durable! This is a favorite of ours. It's so easy to use. This is an excellent meter to buy if it's your first one. Very easy to read... just look for a reading between 2 and 7 mG. Runs on 9v batteries, not
Green light - "Safe" 0-2.5 milli Gauss
Yellow light - "Caution" 2.5-7 Milli Gauss
Red light - "Danger" 8 Milli Gauss or higher
These are not in a blister package but they are brand new right from the factory.