With a crank, you can Taskmaster Steve Ovi. Buy another signature version of ibanze 7V Steve vai, which looks pure (funny). Seriously, you can't play with the crank, so don't buy it. First, it's very troublesome, especially the tuning. If you buy a cheap one, the strings will be out of tune after the second use. (of course, you can also engage in a series of locks. Second, it is more expensive. Three: you can't play ... double shaking means you can lower or raise the strings, and single shaking can only lower them. It will have more effects and some skills, such as clicking on strings, arpeggios and overtones.