That’s a Soundbrenner Core Steel. It features smart vibrating metronome, contact tuner, db meter and it also works as a smartwatch getting notifications from the phone (if paired). I used it as a metronome, very helpful when live looping and in other contexts. You can get it (or any other soundbrenner model) with a 20% discount using the code BELIBAT20 at checkout: https://soundbrenner.com ;). Source: almost 3 years ago

The Soundbrenner Core gives you a smarter and more reliable set of fundamental music tools in a premium wearable. It serves as your everyday watch plus a 1) vibrating metronome 2) contact tuner 3) dB meter and 4) smartwatch. Learn more on soundbrenner.com. Source: about 3 years ago

Have you checked out SoundBocks? https://soundboks.com. Source: about 1 year ago

I had a look at the SoundBoks this weekend at an event I was playing at. It had only a 10ms delay which was pretty awesome. This is out of your price range at 1000 USD, but mentioning here for anyone else looking for wireless portable speakers: Https://soundboks.com/. Source: about 1 year ago

Starting Monday, April 4 at 4PM CET/7AM PST—and repeating every Monday at the same time for the following weeks—we will make a limited number of batteries available for sale on soundboks.com through the regular product page. We’re limiting purchases to only ONE PER CUSTOMER. It will be first-come, first-served, and when the week’s supply is gone—it’s gone. But there will always be the next week :). Source: about 2 years ago