Single Key Button of 433Mhz frequency wireless calling system

wireless call button (1 key: call  2 keys: call, cancel 3 keys: call, cancel, bill）

restaurant hotel supermarket coffee shop waterproof wireless wrist watch receiver

waiter call button table call button used for restaurant, hotel, hospital, etc. 

Y-O-C: one CALL key; Y-Cancel (cancel stick) widely used for restaurant, cafe, bar, drink service.