Your body actually undergoes 4 or 5 cycles of approximately 90 minutes each night.
Be that quality service customers can lean on and you will profit. The original two on their own above list are valuable because deep sleep and REM the actual two most crucial stages of sleep. https://www.Streetinsider.com/Press+Releases/Unlocking+The+Body+Begins+Offering+Flotation+Therapy+In+Puyallup/15388647.html