Culligan RDA-150 RainDisc Shower Optional Hi-Lo Arm, Chrome Finish For use with RDSH-C115 RainDisc shower filtration shower head Installs between your existing shower arm and the RainDisc showerhead to any standard 1/2-inch threaded shower arm Extends the length of the shower filtration system to enable the shower head to be mounted directly above, creating a true rain shower Chrome Finish Adjustable Height