There are 4 ringers on the back of the shower head, because the shower head is very heavy! For the shower head, 2 shower arms are needed, the shower head is so large, if 1. Shower arm can't make the water come out stable! LED Works by Water Flow , No battery is Needed.
LED Color:Blue, Green, Red. When the temperature is below 30°C. LED turns green when the temperature is between 31°C-40°C. LED turns red when the temperature is between 41°C-45°C. Working Hours:17:30pm-4:00am(us time PDT).I describe items as well as I can. If I have missed something, please let me know. If you have any questions, please be free to contact with us, we will answer your questions ASAP. The item "20Matte Black LED Shower Head Ceiling Mounted Rainfall Large Shampoo Sprayer" is in sale since Thursday, December 24, 2020. This item is in the category "Home & Garden\Bath\Showers, Bathtubs & Parts\Shower Heads & Combos". The seller is "upofaucet" and is located in NJ. This item can be shipped to United States.