This wireless calling system utilizes stable, long-distance wireless technology with strong anti-interference capabilities. It is suitable for various environments including hotels, restaurants, cafes, and offices. The receiver display features a modern design and shows the time and date. Both the display receiver and call buttons have an IPX4 waterproof rating. The system includes 30 compact call keys, which can be mounted or carried. It operates on a 433.92MHz frequency. Specifications: Item Type: Wireless Calling System Material: ABS Display Receiver: - Working Frequency: 433.92MHz - Size: Approx. 210 x 140 x 30mm / 8.3 x 5.5 x 1.2in - Receiving Sensitivity: 105dB - Decoding: Learning Code - Waterproof Grade: IPX4 - Working Temperature: -20°C to 60°C Transmitter: - Working Frequency: 433.92MHz - Battery: 2 x CR2032 Lithium Battery (included) - Transmitting Current: 10mA - Standby Current: Less Than 1uA - Open Distance: More Than 200m/656ft - Key Life: 1 Million Times - Waterproof Grade: IPX4 - Working Temperature: -20°C to 60°C - Function: Call Package Includes: 30 x Transmitters 30 x Stickers 1 x User Manual 1 x Display Receiver 1 x Power Adapter Cable