Tristar High-Performance Headset Compact, lightweight headset with superior acoustics and sound reception Reduces background noise and incoming loud tones while enhancing call clarity Quick Disconnect lets you leave your desk while the caller remains on the line Three-point, over-the-ear design for stability and comfort. Four earbud sizes. Requires either PLNP10 or PLNM12 adapter or PLNA20 or PLNCA10 amplifier (all sold separately).