Located in a certain prefecture shrouded in urban legend lies a women's vibrator manufacturing factory. Within this bizarre facility, workers conduct production inspections using their own bodies on a daily basis. This time, we infiltrated the long-concealed manufacturer's factory and managed to record on camera the testing process of a prototype. The inspection involves intense piston-like movements, and these extreme scenes have finally been revealed. This stage is the most crucial checkpoint in the manufacturing process, directly determining the product's performance. The raw, unfiltered reality of this operation unfolds as a truly shocking spectacle.