Smart Self-powered Wireless Doorbell Ring for Apartments Classroom Kitchen

Specification:  Product: Doorbell Transmitter;  Product weight: 45g;  Working voltage: self-generation;  Standby power consumption: 0W;  Wireless frequency: 433.92MHz;  Working temperature: -10℃-60℃;  Distance: Outdoor about 80M Indoor about 30M;  Product: Receiver;  Product size: 83x48x23.5mm;  Product weight: 59g;  Working voltage: 110-240V AC;  Standby power consumption: 0.5W;  Wireless frequency: 433.92MHz;  Working temperature: -10℃-60℃;  Distance: Outdoor about 80M Indoor about 30M;    Package Includes:  1 * Doorbell Transmitter;  1 * Doorbell Receiver;  1 * Manual;