One 48in. gold flat disc scalp electrode.
Choose 48in. electrodes for use with most desktop amplifiers including the NeuroAmp, the Brainmaster and the J&J C2.
Choose 16in. electrodes for use with the Thought Technology procomp amplifiers or any wearable amplifiers such as the Pocket Neurobics pendant, or when using a shielded cable with a desktop amplifier.