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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-17 · 7 min read · Independent comparison
• GREYOLK's biggest strength: a genuinely swim-ready spec sheet — IP68 sealing, a built-in 32GB MP3 player with up to 6,000 songs, and bone conduction sound that leaves your ear canals open to the water and your surroundings.
• GREYOLK's biggest trade-off: Bluetooth doesn't work underwater, so laps have to be swum in MP3 mode, and you're tied to a magnetic charging cable for both charging and file transfers.
• NUPLEA's biggest strength: a charging case that stretches a 4-hour earbud session into up to 48 hours of total playtime, with a digital display so you always know what's left in the tank.
• NUPLEA's biggest trade-off: IPX7 is a splash-and-sweat rating rather than a swim rating, and the battery depends entirely on remembering the case.
• Pick GREYOLK if swimming, snorkeling or boating is the point of the purchase.
• Pick NUPLEA if you want an open-ear companion for running, cycling, gym work and long days away from a charger.
The GREYOLK set is built around one clear idea: bone conduction audio that survives the pool. Its IP68 rating means it's sealed against water, sweat, rain and dust, and the brand explicitly describes use with a swimming cap, goggles and earplugs. Because bone conduction drivers sit outside the ear canal and vibrate through the cheekbone, you keep your ears open — which matters a lot when you're sharing a lane, walking a busy road, or just want to hear the lifeguard whistle. At 32 grams (34 g per the item details) with an ABS open-ear frame and a wraparound titanium band in the description, it's designed to stay put through movement rather than clamp down on your head.
The feature that makes it a swimming product rather than just a waterproof one is the built-in 32GB memory. Bluetooth doesn't travel through water, so the GREYOLK switches to a local MP3 player instead — double-click the power button and it plays files straight from internal storage in MP3, WMA, WAV, APE or FLAC. That's enough capacity for thousands of tracks, and you manage it by plugging the magnetic charging cable into a computer and treating the headphones like a USB drive. Connectivity when you're dry is Bluetooth 5.4 with a 10-metre range, and the 15mm bone conduction driver covers a 20 Hz–20,000 Hz range at 8 ohms. Battery life is quoted at up to 8 hours of playback or talk time after a 1.5-hour charge from the 150mAh cell, and the package includes a cable and manual, backed by a 2-year manufacturer warranty. Controls are physical buttons, with active noise cancellation listed for the Bluetooth side.
NUPLEA Open Ear Bone: Who It's For
The NUPLEA Open Ear Bone takes the opposite approach: instead of one self-contained swimming device, it's a clip-on open-ear earbud pair with a digital-display charging case. The earbuds rest gently on top of the ear rather than inside it, which the brand frames as lighter and more breathable than in-ear designs for long wear. Each earbud runs about 4 hours on a single charge and takes roughly an hour to top up, but the case adds another full charge cycle, bringing total playtime to a quoted 48 hours. The LED display on the case shows remaining battery in real time, so you're not guessing whether you need to plug in before a run.
Audio comes from a 16.2mm vibrating diaphragm driver — the brand says it's three times larger than typical wireless earbuds — paired with directional audio technology for clearer voice pickup on calls. In practice that combination points to a fuller low end and better phone-call clarity than you'd expect from a tiny open bud. There's also a built-in mic and full button control: play/pause, track skipping, volume up and down, Siri activation, and answer/hang up/reject calls. Buttons instead of touch means fewer accidental skips when you adjust the buds mid-stride.
The rating is IPX7, which covers sweat, rain and splashes — running, fitness and exercise are the stated use cases. It's not a swimming rating, and the brand never claims underwater use. Bluetooth 5.3 handles the wireless connection, the colour is Blue-A, and the package includes a cable with a 1-year warranty.
Who should buy it: runners, cyclists, gym-goers and commuters who want situational awareness plus a case that keeps everything charged for days. Who should skip it: swimmers, and anyone who'd rather not depend on a case at all — once the case is empty, you're back to four hours.
• Best for actual swimming → GREYOLK Swimming Headphones. IP68 plus a built-in MP3 player is the only combination here that works in the water.
• Best total battery life → NUPLEA Open Ear Bone. Up to 48 hours across the earbuds and case versus up to 8 hours on a single GREYOLK charge.
• Best for long runs and gym sessions → NUPLEA Open Ear Bone. The case lives in a pocket or bag, so you're never hunting for a charger mid-week.
• Best for phone-free workouts → GREYOLK Swimming Headphones. 32GB of internal storage means no phone required at all.
• Best for calls and voice assistants → NUPLEA Open Ear Bone. A built-in mic plus directional audio and Siri activation are spelled out; GREYOLK lists talk time but the design is aimed at playback.
• Best for battery transparency → NUPLEA Open Ear Bone. The digital display on the case shows remaining power in real time.
• Best for wet-weather and sweat-heavy training → a tie on paper. GREYOLK carries the higher IP68 rating, but NUPLEA's IPX7 is fine for rain and sweat.
• Best warranty coverage → GREYOLK Swimming Headphones. Two years versus one.
In my opinion, the right answer comes down to one question: will these get wet on purpose? If yes, I'd buy the GREYOLK Swimming Headphones — the IP68 sealing and 32GB MP3 mode are the only way to get music in the pool without a phone, and the 2-year warranty adds peace of mind. If your training happens on dry land, I'd buy the NUPLEA Open Ear Bone instead: the charging case turns a modest 4-hour bud into something you can rely on for days, and the larger driver plus built-in mic make it the more versatile everyday pair. Swimmers, take GREYOLK. Everyone else, take NUPLEA.
No. Bluetooth signals don't carry through water, and the brand states Bluetooth isn't supported underwater. You switch to the built-in MP3 mode instead — double-click the power button to toggle between Bluetooth and MP3.
They're rated IPX7, which covers sweat, rain and splashes during running or fitness use. They are not marketed as swimming headphones, so I wouldn't plan on laps with them.
How do I put music on the GREYOLK headphones?
Per the specs, NUPLEA wins on total time: about 4 hours per charge and up to 48 hours with the case, while GREYOLK quotes up to 8 hours of playback or talk time from a 1.5-hour charge. For a single continuous session away from any charger, GREYOLK's 8 hours beats NUPLEA's 4.
Both are budget-friendly open-ear designs, and pricing shifts over time. Check the current price on Amazon using the button on this page before deciding — I don't quote figures here because they change so often.
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