... one key call button Improve work efficiency , satisfaction 100% warter proof CE certificate WITOP WIRELESS CALLING SYSTEMWidely ues in restaurant , ... KTV, hotel , coffe house and so on.Wireless call button , 10colours for your choice. 1 key ,3key. Water ... the components of the wireless calling system?1. Wireless receiver, installed on the count 2. Call button, installed on each table3 ...