http://www.kasina.co.uk/HowToUseKasina.htm
Probably the best system available, uses include meditation, anxiety/stress reduction, relaxation, entertainment, focus, learning and more.
The way it works is flashing lights and synchronized binaural beats are produced by the machine at specific brainwave frequencies, the brain will follow the rate of these to match the frequency.
Comes complete boxed, unused present. Working perfectly.
Due to hygiene reasons I will not accept a return on this item, so do not buy if you do not know if this equipment is suitable for you. These machines are not suitable for epileptics or people who suffer from seizures.
More info on Manufacturer web site below:
https://mindplace.com/products/kasina-mind-media-mediatation-system