The Bluetrek Metal is an ultra light, ultra slim Bluetooth headset; constructed mainly from metal it is only 4mm thick and weighs less than 5.5 grams. Featuring a unique polished aluminum case you can enjoy hands free conversation in comfort and style. The headset offers up to 5 hours talk time and up to 16 hours standby. Can be worn with or without earhook (2 sizes supplied). Can be charged with USB adapter. Supplied with 3 sizes of in-ear bud and 3 sizes of flat ear buds. Size 49.8mm (l) x 15.6mm (w). Operating Range up to 10m. Bluetooth specifications V2.0