-The Latnex MG2000T is a good meter for low frequency magnetic fields,
-the range is 30-2000hz, it is able to measuring power lines and electrical appliances, electrical networks in general.
-It is not able to measuring radio frequency electric fields like phones, wifi, etc..
-Powered by stylus batteries, autonomy over 10 hours.
MY PERSONAL OPINION: for magnetic fields only, however a good product, very good!