This manual describes the BBK T-21 telephone system, including the base (座机) and up to four sub‑phones (子机). It explains the device’s advanced 2.4 GHz digital communication technology, key features such as call transfer, three‑way calling, volume control, night‑light, and customizable ringtones.
Installation steps, registration procedures, charging instructions, setting adjustments, and a troubleshooting section are provided, along with technical specifications and after‑sales service information. This manual is written in Chinese.
| Sub‑phone transmit power | <25 mW |
|---|---|
| Operating frequency | 2.4 GHz (95 channel) |
| Operating temperature range | -10 °C to +40 °C |
| Power supply | 220 V 50 Hz |
In standby mode, press and hold the 【音量】 key for about 3 seconds; the volume will cycle through the available levels.