pro 710 life pid heat controller thermostat - precision low temp aromatherapy heated diffuser pid temperature control 710 life aromatherapy diffuser #1 rated !! the benefits of aromatherapy is been proven by science now you too can own the only ac powered enail to win an award for best product the cup winner! for a great price!! all brands are not created equal, have comfort in buying a unit direct from us the manufacturer, get quality support you deserve, and replacement parts are available so it can be a long term purchase rather than a cheap experience that breaks fast! unit comes with one nail (pictured are 2 inserts installed correctly) our product will last and last and last! also available are these 4 different aromatherapy oils. please check them out also http://www.amazon.com/dp/b00zigvgh2 lavender (night time, peace) http://www.amazon.com/dp/b013pwi70y lavender (night time, peace) http://www.amazon.com/dp/b0019lww9q grapefruit (morning, energy) http://www.amazon.com/dp/b000w3v9hi orange oil (clarity) cautions: