Review Danish company NextLink may claim its Invisio G5 is the world's smallest Bluetooth headset - it's certainly one of the tiniest we've seen - but if you think the brandname means no one's going to spot you're wearing one, think again. However, we're getting ahead of ourselves - beyond its size, the G5 has some other neat touches.

NextLink's Invisio G5: big picture, small headset

The first is the charger. Looking like an outsized Zippo lighter, the charger is a matt-black plastic box in which you place the G5 then close the lid to charge it up. There's a mini USB connector on the charger's base that takes a cable from the AC adaptor.

That's not all: there's a battery on board too, which NextLink claims is good to re-charge the G5 five times once it itself is charged up. The charger is incredibly light, so it really does double as a carrying case and a charger.

The next point in the G5's favour is its novel ear attachment. Most Bluetooth headsets rely on some kind clip that goes around the back of your ear. The G5's fits inside it. If that sounds uncomfortable, we can hopefully reassure you that it isn't, no more than any other headset.

The G5 itself is a 16mm long, 13mm diameter tube with a speaker grille at one end and a blob that holds the microphone and controls on the other. The tube section's clad in shiny black plastic, but the other bit's matt black. The outer-facing part of the headset is almost entirely taken up with the on/off/take call switch, and there are tiny volume up and down buttons on the top and bottom edges of the G5.

Yes, we're afraid to report, there is a flashing light, but here it's discreetly tucked on the inside face of the headset. This is a very nice touch, and should appeal to all those folk who fancy a Bluetooth headset but are put off by the idea having a blinking blue light on the side of their head.

Out of the box, the 6g G5 is small but it clearly won't fit into or onto your ear. Alongside it, you'll find a baggie containing two rubber things that look like giant tadpoles. They're actually the G5's novel clip, one for the left ear, the other for the right. The thick end fits neatly into a groove running around the end of the headset, and it's moulded into a rough cone that points into the ear canal.

The tail, you bend over against the body of the headset and then release once you've put the G5 in place. The tail springs gently back and tucks itself into the folds of your ear, anchoring the headset.

It's more comfortable than it looks

It sounds odd, but it works. If the tail's too long, just trim a bit of the end off, NextLink suggests, but we didn't need to. The tail isn't spring-loaded, so there's almost no pressure on your ear, but it's elastic enough to hold the headset in place. You can give your head a good old shake, and the G5 will stay where it is.

With the G5 so sited, you can accept a call by pushing its outer-most face. Tweaking the volume is rather more fiddly, but the buttons poke out far enough for you to be able to feel your way to them quickly, and they have a good movement to them.

We found using the G5 to be as good as it gets with Bluetooth headsets. These things are never going to be totally discreet. Make them flesh-coloured and they look like old NHS hearing aids, and any other colour makes them stand out against all but the brownest of skins. But the G5 does a pretty good job - again, having no visible flashing light helps - and it's as comfortable to wear as any compact headset on the market today.

World's smallest headset?

Size does, however, affect its performance. Making and taking calls, we found that while callers could hear us just fine - which is no mean achievement given how far away the microphone is from your mush - they came across as a little distant and tinny to us.

Now, we've tried a range of Bluetooth headsets, and we've yet to try one that generates the same sound as holding a phone up to your ear, so we don't want to give the impression that the G5's output is poor - it isn't. But there is a price to be paid as you miniaturise the speaker.

The rubber earpiece doesn't go so far into your ear as to muffle out external sounds to any real extent - it's not like those in-the-ear noise-reduction earphones, for instance - and may actually muffle the sound a bit.

NextLink quotes a talk time of four hours. That's not long as far as modern Bluetooth headsets go. Jabra's almost equally tiny JX10 will let you chat for six hours and will run for 200 hours between charges if it's unused. That's 50 hours more than the G5 can manage, according to NextLink's specs.

The G5 weighs 6g to the JX10's 10g, but that difference is barely noticeable. However, the G5 is by far the smaller of the two, and it doesn't have a big round-your-ear clip, of course.

The G5's case-cum-charger: strike a light

We got just over four days' usage out of a single charge of the G5's battery, and made around an hour's worth of calls. Not fantastic power performance, perhaps, but then the G5 does have its wireless charger. The G5 fits into it even when the ear clip is attached.

Since the charger can power the headset even when there's no AC connection, NextLink likes to say the G5 actually has a talk time of 20 hours - five times four. Charging the G5 up takes around three hours, and curiously the charger was still registering full when the headset was done. We doubt that's actually the case, but it bodes well for future charges. As when the charger finally gives up the ghost and needs recharging itself, we'll let you know in the comments.

One flaw with the charger is the arcane set of codes used to display each device's power status. The charger has a row of five green LEDs: the sequence in which the light up shows you whether the G5, the charger or both are charging, or indeed charged. You can't charge the G5 directly, which is probably a good thing: our JX10 bit the dust because the tiny power connector built into the headset broke through frequent use.

Of course, a new JX10 costs around £50 - £30 less than the G5. We liked the JX10 - it was comfortable and the sound was good - but the G5 just comes out on top. There's not much to choose between then in weight, but the G5 fits so much better, and despite being smaller is less fiddly to use, thanks to the JX10's too-tiny controls.

Verdict

The Invisio G5 is truly tiny as far as Bluetooth headsets go and one of the most discreet that we've seen. Its novel earclip not only works but is comfortable too - despite its looks - and while we've had better sound out of other headsets, the G5 is entirely usable even in a noisy car. And the smart charger means it'll run and run.