Mood's bracelets (screenshot from website)
The bracelets, as described on the company's website, are brightly-coloured silicone bracelets, currently available in 10 smiley emoticons corresponding to different moods and available individually or in a pack.
As the free daily 20 minutes reports they're a "cheap, easy and fun way to express what mood you're in" and much to the surprise of their creators - two French entrepreneurs - they're already proving to be a hit.
And not just with teenagers as Florence Bougault, one those who came up with the concept explains.
"The idea came to Stanislas Henriot and me when we were thinking about all those emoticons that are being used in text messages and chat rooms and which we're very fond of ourselves," she said.
"They're aimed primarily at teenagers, but to our surprise we've seen a lot of mothers buying and wearing them or swapping them with their children."
Smiley (from Wikipedia)
Hardly surprising perhaps as the bracelets have had a healthy dollop of free promotion.
It has come in the form of this year's Secret Story - a French version of the TV reality show Big Brother, only different but by no means better - in which the candidates can (if you're watching closely) be seen wearing them.
And as the show, broadcast throughout the summer, has a daily audience of around 2.4 million viewers for its early evening slot, that's pretty nifty bit of product placement.
As if to emphasise that Mood's is a trend not just in the making, but fast gathering momentum, the French news website Melty.fr is also calling them the 2011 summer must-have among teenagers
And it should know what it's talking about as it's a site specifically aimed at teenagers and young adults.
In fact Google "Mood's bracelets" here in France and you'll soon come up with several sites and blogs talking about how they've already become the fashion accessory for summer and are expected to become all the rage as new ranges are introduced for the autumn.
Next up - coloured elastic bands as glorified fashion statements?
Whoops - they've already been and gone in the form of Sillybandz.