Zeus II is more expensive than flash disk, because Zeus II is easier to use than flash butterfly. Zeus II is an old brand with a good reputation. Fat face and thin face are suitable, and the effect of lifting and firming is also very good. However, the flying butterfly is not suitable for people with small faces, because its probe is very flat and often can't completely touch the skin, resulting in failure to work. So Zeus II is more effective and more expensive than flash drive.