New in plastic package, Universal (multi-model) 2.5mm Jack Black Mono Boom Mic Handsfree Earpiece Headset. Plantronics M60 Universal Black and Dark Gray 2.5mm Jack Mono Boom Mic Handsfree Headset NEW. Crisp clear audio, lightweight, and fits comfortably. Includes a black shirt, collar, tie, etc. secure clip and optional use left and right audio channel isolation speaker cups. It can be used on either the left or the right ear. This earpiece allows you to talk on your cellphone and keep both your hands-free. Use this handsfree headset while you walk, work, or drive for convenience and staying safe. The simple, wired design is a plus for those seeking consistent performance without the complexities of wireless alternatives. * Depending upon model connected, built-in on/off button switch will either function as an on/off microphone mute button or an answer/end cellular calls button key. Models vary upon supported features. ** Headset can be used with our 3.5mm jack conversion adapter to connect to 3.5mm headphone jack port devices. This way, the user would be able to connect to both 2.5mm devices and 3.5mm devices. Please see our other listing for this type of adapter.