Claimed to be the world's slimmest Bluetooth headset, the Bluetrek Metal is quite simply a stunning piece of industrial design. Although it’s without doubt one of the most stylish headsets we’ve reviewed, questionable incoming audio may turn many potential users elsewhere.

The Bluetrek Metal is light, compact and elegant. Available in silver and black finishes, the headset is constructed almost entirely of metal (hence its name). Bluetrek claims the material won't lose its finish. It is just 4mm thick and weighs only 5.5g but it feels surprisingly sturdy and well built.

Operation of the Metal is simple, with just three buttons on the unit. Unfortunately, the small size of the Metal doesn’t help in this regard; the talk and volume up and volume down buttons are incredibly small, and therefore best pressed with the edge of your fingernail. Even the smallest of fingers will find the buttons difficult to press accurately. Thankfully, the in-ear style means the headset is comfortable to use even for long periods. Bluetrek includes six different-sized ear buds in order to provide the best fit possible.

Pairing the Metal with your mobile phone is as simple as pressing the talk button for seven seconds. A tiny LED on the back of the unit will denote pairing mode by quickly cycling between short blue and red flashes. Search for the Metal in the Bluetooth menu of your phone, enter the default passcode (0000) and pairing is complete.

Performance is a mixed bag. Our callers had little complaint with outgoing audio, with our voice projecting through the microphone loud and clear. Unfortunately, incoming audio through the tiny speaker is a hit and miss affair. It fluctuated regularly, from passable to distorted. Depending on background noise, it can be difficult to hold a conversation, especially if there is any wind. The tiny microphone is affected by even the slightest wind.

The Metal has a flexible USB charger and adapter. Plugging into any standard USB port, the charger allows the base end of the Metal to slide into a special slot for recharging. A USB car charger is also included. There is no AC adapter in the sales package, although Bluetrek is generous with included accessories, offering a plastic belt clip and two ear hooks.