Bimodule Synchronous Test -- EMF meters can test both radiations in electric field and magnetic field at the same time for precise result.Sound & Light Alarm -- Radiation detectors will assess the test result and it will automatically alarm when it's over the safe value. Alarm Threshold: Electric: 40V/m; Magnetic: 0.4TEcofriendly & Fashion -- USB rechargeable. Portable and simple design makes digital radiation testers are easy to carry around and do field measurement.Data-Locking & Backlight -- Press one botton to lock the data and clear display with blue bakclight allow you to easily read results. Accuracy: 1V/m for Electric, 0.01T for Magnetic.Measure Temperature -- Swicthable temperature units ( and ). 0C-50CColour: blackMaterial: ABS plasticSize: about 133 x 60 x 25mmPackage Contents:1 x electromagnetic radiation detector1 x USB cable1 x English manualOnly the above package content, other products are not included.Note: Light shooting 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 +/- 1-4cm.