It has a built-in battery which lasts around 10 hours and charges via USB (no charger is included, just a USB cable).
Audio input is via a standard minijack and plugging in a cable turns the unit on. Unplugging it turns it back off, so you don't need to worry about accidentally draining the battery.
Available in white or black, the Wowee One Slim has a traditional cone speaker which faces upwards, and an unusual Gel Audio driver underneath.
The 2W speaker sounds pretty much as you'd expect - rather tinny and lacking in bass, although its volume will be an improvement on any laptop, smartphone or tablet speakers.
However, place the gel driver on a suitable surface and it will turn it into a speaker to produce bass frequencies.
We tested the Wowee One on many different surfaces from wooden coffee tables and cabinets to doors and windows. The results varied from no improvement to stunning bass that eclipsed any other portable speaker we've tested, including Soundmatters FoxL v2.
The best results came from a pine wardrobe which acted much like a traditional speaker cabinet and resonated with amazing bass, adding a huge amount of depth and presence to music. Windows also tended to yield good sound, but any surface thicker than around 20mm wasn't much good as it didn't vibrate.
For vertical surfaces such as windows, you can buy a set of gel pads: semi-permanent sticky pads which hold the speaker in place. There's also an optional hard case, which costs £10.
Unlike the Wowee One Classic, the Slim's predecessor, there's now a battery indicator. An LED shines green when there's less than 10 percent power remaining. Charging time will depend on the power source.
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