Hear it all-music, calls and more. Plantronics M50 Bluetooth headset streams audio form your Smartphone and makes every call worry-free with extended battery life, whispered alerts and noise reduction features. Monitor the battery life automatically on your iPhone. Rechargeable non-replaceable lithium ion polymer. Bluetooth has a working “range” of up to 33 feet between the phone and headset before audio degrades and the connection is lost.