This EMF meter can be used to test the radiation value of the surrounding environment, and measure the electromagnetic radiation intensity around household appliances and industrial equipment such as computer, printer and AC. Or , etc. (Can' test phones) Test frequency ranges from 50HZ to 2000HZ. The numerical contrast is obvious, suitable for the measurement demonstration of the effect of radiation products and personal understanding of radiation. Portable, easy to use, fast reading on a clear LED screen. Suitable for beginners to understanding, studing of radiation, simple use in . When you ' need to use it for a long time, please remove the battery to save. Colour:black Material:ABS Package Contents: 1 x emf meter (6F22 9V battery not included) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin