Feature: 1. Using radio frequency wireless technology, the system is stable and the wireless receiving distance is long. 2. Fashionable appearance and novel design, display time, year, month and day, support 400 pagers, support single-button or 4-button pagers. 3. Call button word selectable, accurate time display and 30‑level digital control volume adjustable. 4. Can name the call button starting with ABCDEF, and use advanced micro‑processing chip to make its performance stable and reliable. 5. Widely used in various places such as homes, hotels, bars, restaurants, factories, workshops, tea houses and offices. Specification: Item Type: Wireless Calling SystemDisplay Receiver Parameter Description: Model: SU-620 Operating Frequency: 433.92MHz Material: ABS Working Current: 100mA±10mA Receiving Sensitivity: 105dBm Decoding: Learning the code Waterproof Rating: IPX4 Working Temperature: -20℃~ 60℃ Button Transmitter Parameter Description: Model: SU-A01 Operating Frequency: 433.92MHz Battery Model: 23A12V Battery Capacity: 60mah Emission Current: 10mA±3mA Standby Current: <1uA Open Distance: >500m Keys: 1 million times Waterproof Rating: IPX4 Working Temperature: -20℃~ 60℃ One Touch: Call How to Use: Button Function Description: Function Key: FUN Confirm Key: ENT Down Button: DOWN Left and Right Buttons: MOVE Up Key: UP F3-2: Last stay display time 1-99 seconds F3-3: Cycle interval time 1-99 seconds F5-3: Number of reports 1-9 F6-1: Delete all pagers F6-2: Restore factory settings (and delete all pagers) F7-1: Time setting. Package List: 1 x Display1 x User Manual 1 x Power 30 x Transmitter30 x Sticker