Jabra BIZ 2400 II Duo "direct connect"  headset bundle comes with a GN1200 bottom cord that connect to virtually just about any phone with a "headset" jack.  In addition the Biz 2400 II Duo has the best noise canceling (UNC) technology in the market today. Jabra Biz 2400 II Duo has an acoustic shock protection, extra padding and the only headset with a 360deg rotating microphone. Jabra Biz 2400 II duo has a microphone has little small holes instead of one larger one as well as foam included inside of the microphone. This design reduces the penetration of air shocks to optimize the call sound quality as well as reduce background noise. 

Key Features:

• Specially engineered for telephones with RJ-9 modular headset jacks. (marked with the word "headset" or have a symbol of a headset).
• This headset package includes the GN 1200 Smart Cord
• Duo Ear (covering both sides)
• Jabra's own Ultra Noise Canceling Microphone - the best in class.
• Large leatherette ear cushions and extra headband padding.
• HD (wide band) sound
• 360˚ degree rotating boom arm
• Built-in Kevlar-reinforced cables.
• 3 year Jabra warranty

For more information, see Jabra Biz 2400 II datasheet