The Starkey S520-NC monaural headset offers superior comfort with a triple XL ear cushion, and has a passive noise canceling mic and SHG Quick Disconnect (QD). 

Product Features and Benefits:

• Over the ear cushion to reduce ear fatigue. 
• Superb sound quality receiver and microphone.  
• Plug and play (USB) - drive included, no downloads needed.
• Passive noise canceling mic. 
• Reliability rate over 99.96%. 
• Connects to all major desk phones with compatible cables (addition cable required). 
• Connects to all major soft phones with available USB connecting cables (additional cable required). 
• Monaural (one ear) wearing style. 
• Triple XL over the ear circumoral cushion type. 
• Starkey QD connectivity.  They offer it in a Plantronics QD (that is the PL version)
• DOES NOT INCLUDE A BOTTOM CORD
• Two year manufacturer’s warranty.
• THIS IS NOT THE MILITARY VERSION, that is the SM520-NC Model