| Model Number | CP-3905= (Unified SIP Phone 3905) |
| Phone Type | Entry-level single-line SIP IP Phone |
| Display | 128 × 32 pixel monochrome graphical display (non-backlit)Cisco |
| Concurrent Calls | Up to 2 calls per lineCisco |
| Speakerphone | Full-duplex (hands-free)Cisco |
| Voice Codecs | G.711a, G.711μ, G.729, G.729A, G.729ab |
| Network Interfaces | Dual-port 10/100 BASE-T Ethernet (LAN + PC pass-through)Cisco |
| Power Supply | IEEE 802.3af PoE Class 1 (48 VDC, 0.2 A); 100–240 VAC, 50/60 Hz, 0.5 A (local adapter, sold separately)Cisco |
| Dimensions (W × D × H) | 5.91 × 2.11 × 8.07 in (150 × 53.5 × 205 mm) (stand folded)Cisco |
| Weight | 20.96 oz (594.3 g) (including handset)Cisco |
| Mounting | Wall-mountable (foldable stand)Cisco |
| Operating Temperature | 32°–104°F (0°–40°C) |
| Operating Humidity | 10%–95% (non-condensing) |
| Storage Temperature | 14°–140°F (−10°–60°C) |
| Protocols | SIP (Session Initiation Protocol)Cisco |
| Key Features | Hold, Redial, Transfer, Mute, Volume control, Message waiting indicatorCisco |
| Color | Charcoal (black) |
| Language Support | Multi-language (Chinese, English, French, German, Spanish, etc.)Cisco |