Valkee, a startup that treats seasonal affective disorder (SAD) with light-emitting headphones, has rolled out version two of its lightweight, inconspicuous ear buds.

The design for Valkee 2 is sleek and unassuming, with few garish design cues to put off any potential new users. Spotted by TechCrunch, the unusual headphones slot into a rather plain silver or black box (it could easily be passed off as a standard MP3 player in the street) with a single button to kick off a new light session.

The idea is that these headphones supplement the natural, positive effects that our bodies receive from everyday sunlight. The ear buds shine light through the ear canal and into photosensitive regions of the brain, improving your overall wellbeing and mental performance.

Valkee says users will feel the effects after just 12 minutes of use each day; hitting the button in the center of the console will then show a subtle circle of light that depletes throughout the session.

Valkee, based in Helsinki, Finland, raised 7.4 million euros ($9.7 million) in funding back in June. It’s an unusual product, but one that could be successful if the positive effects are noticeable and significant. The Valkee 2 is available to pre-order now for 199 euros (roughly $269) plus delivery costs and is due to ship sometime in October.