Description :  KERUI F64 Wireless Call Button for Welcome & Alram Service Calling System 4 Keys Transmitter CALL BILL CANCEL DRINK 433MHz   Specification :  Working Frequency: 433MHz Wireless Distance: 100M in Open Area Wireless Coding: PT1527、 EV2262 4 Buttons Call Bell: CALL、 BILL、 DRINK、 CANCEL Size: 60 x 60 x 13mm   Package includes :  1 x KERUI F64 Call Button   Details pictures :