8.33/25 kHz Ground to Air Radio with Class Leading 1500 mW powerful Audio. Compact, waterproof and durable body (IP67/IP54 and MIL-STD-810-G) Built-in Bluetooth for Hands-Free Operation Large capacity battery pack provides 17 hours* of long battery life. LCD and key backlight for night time operation. Compatible* with Third-Party Aviation Headsets** *5/5/90 Duty Cyle ** Optional headset adapter OPC-2401 required.