Utilizes RF wireless technology for a stable system with a long wireless reception distance of over 200 meters in open areas. Features a waterproof design with an advanced microprocessor chip for stable and reliable performance. Constructed with a durable ABS material shell, resistant to wear and tear. Operates at a transmission frequency of 433.92MHz. Simple setup: just set up the machine first, then press the button on the transmitter for the receiver to get the reminder. Widely applicable in homes, hotels, bars, restaurants, factories, workshops, clubs, bowling alleys, massage rooms, churches, country clubs, health clubs, offices, and more. Item Type: Wireless Pager Call Button Material: ABS Operating Frequency: 433.92MHz Battery: 2 x Built-in CR2016 Button Batteries (included) Battery Capacity: 80mAh Emission Current: 10mA±3mA Standby Current: <1uA Open Distance: >200 meters Key Presses: 1 million times Waterproof Grade: IPX4 Working Temperature: -20℃ to 55℃ Four Keys: Ring, Checkout, Order, Cancel Package includes 10 call buttons and 10 films. Customer satisfaction is our top priority. Contact us immediately for any issues like damage or incorrect quantity upon receipt. We strive to provide the best after-sales service.