The Brain Tuning Fork Set uses two forks struck together creating a binaural or difference beat which corresponds to one of four brainwave states:
Beta: Alert, normal waking state for everday conscious thinking, clear perception, concentration, critical thought
Alpha: Relaxed, at peace, calm, daydreaming, visualization, integration of feelings, memory, enhanced learning ability, enhanced serotonin release, mood lift
Theta: Shamanic experience, lucid dreaming, creative meditation, pre-sleep, intuition, inner guidance, inspiration, introspection
Delta: transcendental meditation, healing of body, production of natural opiates, harmony, insight, deep meditation, sleep, regeneration
Use the fundamental fork along with the appropriate brainwave fork to experience benefits of the brainwave state.