Plantronics UPMX510X1 Headset Maximum Comfort: Innovative FlexGrip design for secure, comfortable fit. Works well with eyewear. Personalized Fit: Includes two interchangeable WindSmart voice tubes. Rotate voice tubes for perfect placement. One-Touch Controls: Easy-to-use mute and volume buttons. Quality Sound: WindSmart technology for optimal voice transmission. Excellent volume for easy listening