Cisco Unified Wireless IP Phone 8821, World Mode Bundle, IEEE 802.11a/b/g/n/ac radio for VoWLAN communications support, The large 2.4-inch (6 cm) color (240 x 320 pixels) display makes viewing easy, IP67 rated for protection against dust and water immersion between 6 inches (15 cm) and 3.2 feet (1m), MIL-STD-810G standard for shock resistance, The phone offers exceptional voice quality with high-definition (HD) voice, A built-in full-duplex speakerphone offers high-quality hands-free communications, The phone supports third-party Bluetooth 3.0 headsets and a 3.5-mm headphone jack for added freedom, The Applications key provides direct access to XML applications such as push-to-talk and Lone Worker, Battery life delivers a minimum of long hours of talk time and very long hours of standby time, Enhanced encryption support for SHA-1 and SHA-2 signatures, Fast, secure roaming using 802.11r and Cisco Centralized Key Management roaming, Automatic certificate renewal - SCEP support,