JBL is crowdfunding a new pair of headphones that use an array of solar panels on their headband to offer potentially unlimited battery life under the right conditions. The Reflect Eternal headphones are live now on IndieGoGo, and can be preordered for $99 with an expected ship date of October 2020.

The crowd-funding campaign is making some pretty ambitious claims about how much extra charge the headphones’ Exeger Powerfoyle solar charging material can get you. JBL says that wearing the headphones outside for just 2.5 hours a day could be enough to get you “virtually unlimited playtime” between charges, for example. However, in order to achieve this it sounds like you’ll have to wear the headphones on a relatively sunny day. Apparently the sweet spot is a lux brightness value of at least 50,000, which Wikipedia suggests requires direct sunlight.

A note on crowdfunding: Crowdfunding is a chaotic field by nature: companies looking for funding tend to make big promises. According to a study run by Kickstarter in 2015, roughly 1 in 10 “successful” products that reach their funding goals fail to actually deliver rewards. Of the ones that do deliver, delays, missed deadlines, or overpromised ideas mean that there’s often disappointment in store for those products that do get done. The best defense is to use your best judgment. Ask yourself: does the product look legitimate? Is the company making outlandish claims? Is there a working prototype? Does the company mention existing plans to manufacture and ship finished products? Has it completed a Kickstarter before? And remember: you’re not necessarily buying a product when you back it on a crowdfunding site.

JBL claims that the headphones can even charge from lighting indoors, although that’ll be far slower than under direct sunlight.

Outside of their solar-charging capabilities, the Reflect Eternals work like any other pair of wireless headphones. They come with support for both Google Assistant and Alexa, and also feature external microphones for when you want to hear what’s going on around you without having to take the headphones off. Oh, and naturally they can still charge over USB as a backup for when the sun disappears.

JBL isn’t the only company to have experimented with adding solar cells to consumer electronics. Outside of the solar-powered calculators I used to use in school, the most successful implementation I’ve come across are Logitech’s solar powered keyboards, which I’ve used on and off again for years without ever having to re-charge. Garmin also announced a smartwatch earlier this year that uses a built-in solar panel to extend its battery life by a couple of days under the right circumstances.