The entrainment rhythm of 7.83 hertz is the frequency produced by Earth and is very grounding. This frequency has been said to help with jetlag, protect from mind control, increase tolerance to stress, promote healing, and stimulate the pituitary to release HGH (helps with muscle development, recovery from injuries, and rejuvenation). Some have said it "leaves you feeling revitalized like you've spent a day in the country." People have reported accelerated healing and enhanced learning. Uses monaural rhythms, and does not require headphones. Contains instructions and two hours of audio in MP3 format. Instant download.