This transmitter detects the opening of a door or window and sends a radio signal to any BELL200 doorbell. - Wireless range up to 50 metres - Battery operated: 1x 3-V lithium (inserted) - Selection button for eight melodies on the receiver - Transmission indicator light - Radio frequency 434 Included with delivery 1x transmitter incl. battery 1x magnet 1x instruction manual Dimensions Transmitter: 38 x 90 x 23 mm (W x H x D) magnet: 16 x 58 x 15 mm (W x H x D) Power supply Battery: 1x 3-V lithium CR 2032 (included) https://elecena.pl/product/18184357/bell-213-3tx-wireless-doorbell-system-door-window-detector 2021-05-01 https://elecena.pl/product/18184357/bell-213-3tx-wireless-doorbell-system-door-window-detector 2023-02-18 https://elecena.pl/product/18184357/bell-213-3tx-wireless-doorbell-system-door-window-detector 2023-04-02 https://elecena.pl/product/18184357/bell-213-3tx-wireless-doorbell-system-door-window-detector 2025-04-03