The small, hand-held and self contained GSR 2™ is a Galvanic Skin Response monitoring device for home biofeedback. The GSR 2 biofeedback unit precisely monitors your stress levels by translating tiny tension-related changes in skin pores into a rising or falling tone. By resting two fingers on the sensing plates you learn to lower the pitch and your stress level. Features: 9V battery (included).Ergonomically shaped for a most comfortable and natural grip. Provides tonal feedback through speaker or earphones. Includes: Manual and instructional CD with relaxation exercise.