Plantronics® Headset For Mobile Phones Comfortable, durable, and lightweight mobile headset offers hands-free convenience anywhere you go. Converts from headband-style to over-the-ear-style. Wear on either ear. Noise-canceling microphone transmits only user’s voice. RF noise shield and microphone adjust switch produce crystal clear calls. For phones with a 2.5mm headset jack. Headset adapter required for mobile phones without headset jack.