Pairing the sunglasses with a phone is very straightforward and the specs can store pairing information for up to eight devices at any one time. You can connect two devices to them simultaneously as long as they're not similar in functionality. So for example, you can have them connected to a Bluetooth-enabled MP3 player and a mobile phone at the same time, but you can't have them connected to two mobile phones at the same time.
As a headset for your phone, the sunglasses perform surprisingly well. There are dual microphones embedded in the frame (just under each of the hinges) and these are used in combination with noise-cancelling technology from a company called Step Labs. Even on a busy street or in a car with the window rolled down callers reported that the TriSpecs did a good job of blocking out background noise. Incoming callers also sounded very clean via the earbuds and there's a decent amount of volume on offer, which is a bonus as some headsets can be a bit on the quiet side.
When it comes to listening to music, the earbuds performed pretty well too. Mids and highs cut through nicely and give good definition to the sound. Our only real complaint is that the bass can be a little weak at times. Whether the transport controls work properly or not will depend somewhat on your phone's Bluetooth implementation, but we used them with an O2 XDA Zest and they worked without any problems.
The sunglasses are supplied with a wall charger, but as this connects to them via a microUSB port on the right hand arm, you can also charge them via a spare USB port on your desktop or laptop if you like. Unfortunately, there's no car power adaptor included in the box, but as these are quite cheap to buy it's not a major omission. It takes about three hours to fully charge the specs and once they're charged TriSpecs says they're good for around seven hours of talk time or five hours of music playing. During our testing period we got around six hours of talk time out of them and four and a half hours for music listening, which isn't far off those quoted figures. This also compares favourably to Bluetooth stereo headsets like the Plantronics Voyager 855 and Bluetrek Duo Stereo.
There's no doubting that the TriSpecs perform well as a headset. The noise-cancelling technology does a great job of suppressing background noise and callers sound clean and crisp via the earbuds. Music streaming also works a treat too. However, the problem with these sunglasses is that they just look so odd that we're not all that convinced that integrating a headset into a pair of sunglasses is a good idea. Still, if you do want sunglasses with integrated Bluetooth functionality, these are, to our knowledge, the only ones on the market at the moment, so we guess on that front they're on to something of a winner.