After a couple years of development and early prototype testing through an Indiegogo campaign, Bose is commercially releasing its noise-masking Sleepbuds. They go on sale tomorrow, June 21st, for $250 from Amazon, Best Buy, Bose, and other retailers. The Sleepbuds are truly wireless earbuds designed to stay in your ears overnight. As you go to sleep, they play audio tracks that drown out typical evening disturbances like street noise, loud neighbors, or a snoring partner.

They don't play music or any other audio from external devices. Period. So forget about streaming Spotify, audiobooks, or podcasts. Nor do the Sleepbuds utilize Bose’s incredible noise-cancelation tech that’s the magic ingredient in products like the popular QuietComfort headphones.

Noise cancelation is great for eliminating the hum of an air conditioner or quieting a noisy airplane cabin, but it tends to let voices and sudden noises through. So Bose doesn’t think it’s the best solution for ensuring a good night’s sleep. Instead, the Sleepbuds “combine passive blocking of sleep-disturbing sounds with a choice of sounds engineered to mask what gets past the blocking by the eartips.” Masking. Not canceling.

The white Sleepbuds weigh 1.4 grams and are the smallest product Bose has ever made, measuring just over 1 centimeter in both width and height. They’re designed to feel weightless in your ears and remain comfortable all night — even for side sleepers like myself. They don’t protrude beyond your ears, so a pillow won’t jam them in further.

Through its own engineering expertise and with the knowledge gained by acquiring Hush, Bose has put a lot of work into miniaturization and making these as tiny as possible. The wireless antenna is actually part of the exterior, and there’s also a silver-zinc battery, transducer, and flash memory inside. That minuscule transducer isn’t cut out for playing music, according to Bose, but works just fine for the “sleep tracks.” The buds won’t die from your ear wax or night sweats, either.

Specially-designed eartips cut back on the loudness of noises, but they’re not enough alone. So Bose built flash storage into the Sleepbuds and filled it with 10 audio tracks that play through the night. (Streaming files from your phone would’ve cut down on the 16-hour battery life.)

All the cliche sounds you’d expect are there, with selections from nature — a running stream, rain, ocean waves, wind, country night, etc. — and other options like brown noise, a dehumidifier, and so on. I’m hoping an oscillating fan is somewhere in there.

You can adjust the volume level for each sound so that it can fully mask whatever noise is sabotaging your sleep. Bose told me that it mastered each audio track to specifically hide the audio frequencies of snoring, traffic, and so on. But you probably shouldn’t have the sleep tracks cranked up too high, since doing so might prevent you from hearing critical things like fire or smoke alarms. That’d be bad.

More audio tracks will eventually be added to Bose’s mobile app for the Sleepbuds, so you’ll be able to swap them in and out as you wish. The app is also where you can set an alarm or keep the Sleepbuds on a timer if you don’t fully trust Bose to wake you up and prefer your regular way of doing things. The Sleepbuds charge in an aluminum case with a Micro USB connection and rubber base for sturdy placement on your nightstand. The case holds an additional 16 hours of power, so you’ll get a total of 32 when traveling before everything needs recharging.

I think lot of people are going to scoff at Bose’s $250 asking price. That’s a ton of money for earbuds that can’t play music, and it’s a drastic premium over the foam earplugs on the shelf at your neighborhood pharmacy. But foam isn’t great in all cases (like for people with tinnitus), and a $50 noise machine might not be worth much if there’s ungodly snoring happening right beside you. Sleep deprivation is awful for your health, so the most important thing is just finding something that works for you. Bose’s nearly 3,000 Indiegogo backers get the best deal, as they’ll be upgraded to production units in the coming weeks after using prototype hardware until now. Early bird pricing during the campaign was as low as $150.

Stay tuned for a full review to see whether the Sleepbuds are worth the full cost for everyone else.