Only the WaterPlay Station combines TOUCH - SIGHT - SOUND sensory interaction into one portable unit. Anywhere you have access to a standard 110 power outlet, you can use the Sensory Station. The calming effect of continuous running water can easily travel with you. It only takes 32 oz. of water to run the unit for as many hours as you want. And when you are done, simply turn it off, remove the water tray and empty it.