One of the better Thermos/Fat Burners I've used in a long time. Also, for the cost (very reasonable), will be very tough to beat. Great focus and ability to concentrate not only in training, but in school and work. Controlled my cravings, improved mood, steady lift in energy and no real crash that i've noticed. Almost like a very smooth and subtle landing. Has not affected my sleep, like most other thermos i've used.