NeuroSky MindWave Mobile is a wireless EEG Bluetooth LE Device. It places a Dry Active sensor at a fixed location over the frontal lobe region of the person's forehead. The Ground and Reference sensors clip on the left ear lobe. The most important benefit of the MindWave Mobile is that when used with BrainTrain's Artifact Correcting Neurofeedback software that it provides a very accurate measure of the amplitude of brainwaves in the Delta, Theta, Alpha, Beta and EMG ranges. It requires one AAA battery (not included) and that the device connected to it support Bluetooth LE. Both Apple iOS and Android devices use Bluetooth LE and we support Apps for these devices. In addition, BrainTrain Apps are available for Windows PC (10 and higher), but is recommended that an additional Bluetooth dongle (sold separately) be used with PCs. This device can be configured to work in countries with both 60Hz (US and North America) and 50Hz electrical systems (Other countries worldwide). The device comes with a 30 day warranty. In addition, a 1 year exchange warranty is available from BrainTrain, Inc. for an additional one-time fee.