I am SO thankful I found the singing straw and Whitney's warm-ups and programs. The straw phonation with the singing straw pro is truly incredible. Based on how my voice is feeling I can customize my warm up and practice to 2, 3, or 4mm with the different straws. I love having the metal straws - SO much better than when I just used a drinking straw around the house - more customizable. the stronger material makes for better resistance and better development of the vocal folds, and the case makes it easy to take them with me wherever I go. I can NOT say ENOUGH about how awesome these are. They are helping me iron out the rough spots in my vocal range, helping me learn to sing with less tension, and helping me learn better ways to prepare my voice for singing at any time of day.