... .It receives 3 groups code at same time 2.With single keypad, easy operation 3.Group calling, Brief Introduction of ... can be used in one siteWith keypad mode, easily operateGroup calling, group cancellingCompatible with all the CS display LED and ... the same timeWith single keypad, easy operationGroup calling, group cancellingCompatible with CS multi-keypads calling unitsUSB port with 5V power supply, ...