When go to the hardware store, orient yourself to the plumbing and outdoor department, you will need fittings to install the valve which is necessary to control the water upon demand.
This one inch solenoid powered valve will be installed in-line of the water supply and shower head, adapter bushings will easily convert the existing half inch typical shower hardware to the inside diameter of one inch, and to be reduced down to the existing half inch size to receive your shower head assembly.
You will need a 1 inch by 1/2 inch reducing bushing this is a male to female fitting. the male one inch fitting will be installed on both ends of the valve, the female end will be accompanied by a 1/2 inch threaded nipple, you need an assorted lengths, this will be determined by the escutcheon (cover plate, I utilized a plastic waste can) you choose which matches your decor, will thread into the existing 1/2' opening vacated by your shower head assembly, and the other end will receive the 1/2 inch male shower head assembly.
Finally, pick up the last component of the retro-fit 110v to 24v transformer, found in lawn and garden near the valve, you will need low voltage wire16-18 gauge thermostat wire with the necessary terminals to connect wires together and receive an auto-like 3 amp fuse.
This transformer will plug into a pass through device- an internet enable switch which allows you to control this switch with your mobile device, the WEMO switch, available under $50.00 and the app is free. Once configured to your wireless network, you can customize it and positioned the app on your home screen.