The RC-28 is designed for use as a wireless call button. She works with receivers UC-260, UC-216, UC-222 and UC-280. Features Nutrition 6 V battery (type L1016) Battery Approximately 1 year Operating frequency 433,92 MHz Operating conditions Indoor Operating temperature from -20 ° C to +50 ° C Humidity from 25% to 75% Storage Temperature from -20 ° C to +70 ° C Compliance with the requirements of EN ETSI 300220, ETS 300683 and EN 50134.