Specification: Item Type: Wireless Wrist Pager Model SU 691 Watch Receiver Parameters Description: Operating Frequency: 433.92MHz Material: ABS Charging Voltage: DC5V Operating Voltage: DC3.7V Rechargeable Lithium Battery Operating Current: 100±20mA (Vibration, Buzzer Mode) 75±10mA (Vibration Mode) Standby Current:10±5mA Receiving Sensitivity: -107±2dBm Decoding: Studycode Waterproof Rating: IPX7 Operating Temperature: -20?-60? Battery Type: Lithium Battery Battery Capacity: 300mAh (Included) Model SU D1 Button Transmitter Parameters Description: Operating Frequency: 433.92MHz Battery Type: Alkaline Battery Battery Type: 12V23A Battery Capacity: 60mAh (Included) Transmitting Current: 10mA±3mA Standby Current: Open Range: Approx. 100-200m / 328.1-656.2ft Push Button: 1 Million Times Waterproof Rating: IPX7 Working Temperature: -20?-60? Single Key: CALL Applicable: Widely used in homes, factories, workshops, clubs, bowling alleys, massage rooms, churches, cos, golf and country clubs, hospitals, health clubs, elderly call alarms and offices, etc. How to Use: Turn on and use packing list: 1 x Watch Receiver 2 x Watch Button 1 x Power Cord 1 x Instruction Manual or 1 x Watch Receiver 3 x Watch Button 1 x Power Cord 1 x Instruction Manual or 1 x Watch Receiver 4 x Watch Button 1 x Power Cord 1 x Instruction Manual See morePROMPT METHOD: Prompting methods are light flash and vibration, light flash and buzzer, light flash, vibration and buzzer, low power consumption display can be flexibly combined. WATCH DESIGN: Wireless watch pager has a stylish watch design and is easy to use. Removable rechargeable battery with long standby time and charging circuit protection. APPLICABLE: Wrist pager is widely used in various places such as home, factory, workshop, general assembly, bowling alley, massage room, church, elderly call alarm and office. HUMANIZED DESIGN: Restaurant paging system supports 4 channels, each channel supports 5 buttons. One button with multiple watch receivers. ANTI INTERFERENCE: Wrist pager supports IPX7 waterproof. Strong anti interference, fast speed and accurate transmission. Operation range of 100-200m in open distance.