| Feature | T21P | T23G | T27G | T53 | T54w | W52P/W52H |
|---|---|---|---|---|---|---|
| Style | Desktop | Desktop | Desktop | Desktop | Desktop | Cordless |
| HD Audio | Yes | Yes | Yes | Yes | Yes | Yes |
| Screen | 132x64 B&W | 132x64 B&W | 240x120 B&W | 360x160 B&W | 480x272 Colour | 128x160 Colour |
| PoE | Yes | Yes | Yes | Yes | Yes | Yes |
| Ethernet | Fast (100M) | Gigabit (1GB) | Gigabit (1GB) | Gigabit (1GB) | Gigabit (1GB) | Fast (100M) |
| Wireless | No | No | No | Optional | Yes | IP-DECT |
| SIP Accounts | 2 | 3 | 6 | 12 | 16 | 5 |
| Programmable Keys | 2 | 3 | 8 | 0 | 0 | 0 |
| Virtual Keys | 0 | 0 | 21 | 21 | 27 | 0 |
| External Key Module | No | No | Yes | Yes (upto 3) | Yes (upto 3) | No |
| Headset Support | Yes | Yes | Yes | Yes | Yes | Yes |
| Loud Speaker | Yes | Yes | Yes | Yes | Yes | Yes |
| Bluetooth | No | No | Optional | Optional | Yes | Yes |
Please note that at least one programmable key will be occupied by the extension number.