Plantronics PW540 (EncorePro Polaris 500 series) is a headset complete with a Plantronics A10 cable that has the RJ-9 "modular" jack. Plantronics PW540 has a 3-in-1 headset design.  It comes complete with three (3) wearing styles.   Plantronics EncorePro is designed with quality and comfort.  Plantronics PW540 provides HD wideband audio, a flex mic, and soft ear cushions.  It's built with real durable and lightweight materials, comfortable for all day use without ear fatigue. 

Key Features:

• This product contains Plantronics HW540 + Plantronics A10 cable

• Comes with three (3) different wearing styles - over the head, on the ear, and behind the head.

• Plantronics PW540 is lightest in its class

• Plantronics Quick Disconnect (QD) for easy disconnect from the phone

• Flexible noise canceling mic boom

• Wideband High Definition audio with SoundGuard technology protects from noise spikes

• 2-year warranty

Important Note: Plantronics Polaris Headsets can only be use with telephones with a headset jack built-in (ie. Nortel, NEC, etc). DO NOT BUY THIS HEADSET WITH A VISTA M12 or M22 AMPLIFIER. If your phone does not have a headset jack and internal amplifier, then the Plantronics H-Series Headsets with an external amplifier such as the Plantronics Vista M22 are a good solution.

<= This headset has a Modular RJ-9 Jack

For more detail information see Plantronics PW540 datasheet