Surface-mounted secondary ring tone device In its surface-mounted version, the secondary ring tone device with capacitor and optical display is used as an additional signalling device for telephones installed in indoor areas. The secondary ring tone device is connected using either a- b or w- wires. A telephone with TAE connector (F coding) can be connected directly to the secondary ring tone device. https://elecena.pl/product/18679662/wk-958-ap-ring-tone-secondary-device 2021-06-06 https://elecena.pl/product/18679662/wk-958-ap-ring-tone-secondary-device 2025-01-29