It charges via USB and has eight settings. It's also got a feature called "cruise control," which means it saves the last 20% of its power until it can tell that you're pressing it hard against you, so the motor will automatically stay as powerful even when things really heat up.
Promising review: "I personally love waterproof toys. Shower time often ends up being playtime for me as well, and so I ordered this really hoping that I had found a new toy to add to my shower arsenal. I was not disappointed. When I told my husband about it, he told me that I need to write a review with an exact quote of what I'd told him: 'If I ever use this outside of the shower, I will need to make sure that I have towel down.' Using it at the lowest setting, I was able to climax in less than two minutes. Normally when participating in self pleasure, I'm only able to achieve climax once, but with the Lelo Sona Cruise it was multiple times, to the point of gushing. If you like fast and hard and intense, then I highly recommend this toy." —Lynblue
Get the Sona Cruise for $73.55+ (available in three colors), or get the original Sona without the "cruise control" feature for $53.95 (available in three colors), both from Amazon.