http://www.simplyheadsets.com.au/wireless/gn-netcom/gn9120-st-wireless-headset-system.html

To keep calls secure, the GN 9120 uses a digital spread spectrum protocol originally developed for secure military communications, and 64-bit encryption. The GN 9120 is a wireless headset that works the way today's in-office professionals work. Offering an unbeatable range of personal mobility in the office, a robust talk time and a host of innovative features and benefits, the revolutionary GN 9120 will give complete wireless freedom in the office.The unique conference call feature lets you hold fully mobile, secure conference calls not restricted to meeting rooms or ruined by crackling speakerphones.
The GN 9120 delivers up to 8 hours talk time. Combined with a fast 90-minute charging time and a full 24 hours standby, you'll have power to take all your calls without interruption.

http://www.simplyheadsets.com.au/wireless/gn-netcom/gn9120-st-wireless-headset-system.html