Features: 1.LONG LASTING BATTERY LIFE: The built in high capacity battery ensures extended usage without the need for frequent charging. 2.PERMANENT CALL RECORD STORAGE: Even in the event of a power outage or factory reset, the call records are permanently saved and will not be lost. 3.VERSATILE CALL COMMANDS: With 33 built in call commands that can be freely customized, the wireless caller can adapt to various usage scenarios. 4.LCD SCREEN DISPLAY: The device features a user friendly menu operation with a clear LCD screen display, making it simple and easy to use. 5.MULTIPLE NOTIFICATION MODES: The receiver combines vibration, ringing, and even a calendar display, providing multiple ways to alert the user. specification:Item Type: Wireless Calling Pager System Material: ABS Number of Connected Callers: 500 Prompt Mode: Vibration, buzz, flicker; Receiving Sensitivity: -110dBm Call Information Storage Capacity: 20 groups Battery Type: Lithium battery Battery Capacity: 250mAh (inclusive) Standby Time: 7 days Button Caller Parameter Description: Operating Frequency: 433.92MHz Battery Type: Lithium manganese battery CR2032 Single Pager Battery Capacity: 240mAh (inclusive) Transmitting Current: 10mA3mA Standby Current: Approx. 200m / 656.2ft Keystrokes :1 million times Waterproof Rating: IPX4 Operating Temperature :-20 to 55 One Key: Call Voltage: 100-240V PackageList: 1 x Watch Receiver 5 x Pager 1 x Charger 1 x Charging Cable 1 x Manual