The Genmu Power Piston is there for when you want something to rub you off into a whole new stratosphere. Slide in the Genmu onacup and then let the robotic piston get to work, thrusting away on your lubricated member up to 240 times a minute in 12 different kinds of patterns.
With a nuanced and textured inner cup, the strong piston will tickle and stroke your shaft and head in ways that a regular lady's body simply cannot achieve. The parts are detachable for ease of cleaning and maintenance, and the whole unit charges up by USB, so once it's fully powered you can carry it to wherever you want to use.
The Genmu Power Piston features: