This is a newly improved product. It's designed to theoretically double the number of nanobubbles generated. By installing it between your existing showerhead and hose, your showerhead will be transformed into one that generates micro-nanobubbles using the popular tornado water flow. The tornado design utilizes four holes for efficient bubble generation. The screw size is compatible with the international standard G1/2. It generates more efficient bubbles than commercially available micro-nanobubble (ultra-fine bubble) products. Benefits: * Micro-nanobubbles penetrate pores and remove dirt. * Dirt floats away just by lightly scrubbing in the bathtub. * The warm feeling after a bath lasts for several hours.