TL;DR: Marshall's Stockwell III portable Bluetooth speaker has officially launched, priced at $249.99. It offers 40+ hours of playtime, true 360-degree Marshall sound, IP55 dust and water resistance, and doubles as a charging bank for other devices.

Marshall's Stockwell III officially launches on Aug. 4.

We first wrote about the announcement back in June, when Marshall confirmed it would keep the price at $249.99 despite adding solid upgrades over the previous generation. Now it's finally available at Marshall and Costco.

The main upgrade here is that the battery life has doubled — Marshall bumped it from 20 hours to 40+ hours, and it charges over USB-C, with a 30W PD charger getting you a full recharge in under 3 hours (or 7 hours of playtime from just a 20-minute quick charge). Water and dust resistance also improves, going from IPX4 on the previous model to IP55, so it can handle much more than the occasional splash.

Sound-wise, it keeps Marshall's True Stereophonic 360-degree audio, powered by a 3-inch woofer and two 1.75-inch wide-band drivers, and backed by a 65W amp for the woofer.

Bethany Allard, who covered the announcement back in June, pointed out that the previous Stockwell II earned praise from PCMag for its "rich bass and bright highs" — so the sound quality here was already solid, even before this upgrade.

Another cool detail: the battery is swappable — instead of tossing the speaker once the battery wears down, you can replace it yourself, along with the front and back grilles, silicone sleeve, and carrying strap. That's not something you see often with Bluetooth speakers, most of which are basically disposable once a part fails.

It's got tactile, amp-inspired controls on top, including a new M-button for jumping straight to your saved presets, plus Bluetooth 5.3 with Auracast support and multipoint connectivity for pairing with more than one device.

It's available now for $249.99 on Marshall and Costco.

Soumya is a deals writer who covers consumer tech, shopping deals, and the products people use every day. With experience writing about everything from AI tools and software to smartphones and home gadgets, she enjoys breaking down product research into clear, useful recommendations. When she's not tracking deals, she's usually comparing products, digging through reviews, and figuring out what actually makes a purchase worth it.