Why be content with one when you can have three? A cooling unit is extremely important to get the best possible flavors and fragrances for the liquids and oils you will use with your Crafty Vaporizer. It makes airflow better and improves your overall experience. Having three spare cooling units is a great idea plus you are saving on postage and time by ordering multiple units at once. These units are a must have for those who want to experience better vaping every time.