Bluetrek Metal Mono Bluetooth Headset (Black) Bluetooth V2.0. 5.5 grams ultra light weight. Up to 5 hrs of talk time and 7 days of standby. Thinnest Bluetooth headset on the planet. Ultra slim, 4mm thickness. Unique Polished Metal Case, luxurious aluminum. Practical belt clip to carry your headset and USB adapter conveniently. USB cable, USB vehicle power adaptor included.