Wireless in-ear headphones might be getting progressively smaller, but they all have one thing in common - a wire connecting the two earbuds together. That's not the case with Earin, a new Kickstarter project that is aiming to become the world's smallest pair of wireless in-ears if its creators reach their crowd-funding goal.

The Swedish company's concept is of two earbuds that work together as a single pair of Bluetooth in-ears, with no cables or attachments - making them more like earplugs than a pair of headphones. With no cables, no LED lights and no integrated microphone, the design team has promised Earin will be as minimal as possible. The buds will ship with several pairs of foam tips for the best seal, and include concha locks to ensure the buds stay in your ears, even when exercising or listening on the move.

Using balanced armature drivers and aptX Bluetooth, the Earin buds should be capable of high quality sound, but the engineers have had to home up with a novel way of recharging them without a cable. Instead of adding charging ports to each earbud, Earin will ship with a capsule for topping up the internal batteries. It's small enough to fit on a keyring and has an internal battery that refills the earbuds when stored.

Up to three hours of battery life from each bud doesn't sound like a huge amount, but considering they can recharge every time you pop them back in their case most people should be able to enjoy their music without worrying about running out of juice on the way home from the office. The capsule itself charges over USB, but the Kickstarter page doesn't make it clear how many times you'll be able to top up the earbuds before the capsule runs out of juice.

At the time of writing, Earin had already raised £129,000 of its £179,000 goal, and with 37 days remaining it seems very likely to reach that goal with time to spare. Kickstarter backers are due receive their Earin headphones around January next year, with a full retail price expected at around £159 once the company is ready to open orders to the general public.