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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-27 · 6 min read · Independent comparison
• RELAXYO Bone Conduction Swimming — biggest strength: an IP68 rating plus 32GB of built-in storage, so you can leave your phone behind and keep listening where Bluetooth cannot reach — including underwater.
• RELAXYO Bone Conduction Swimming — biggest trade-off: 7 hours of playtime per 1.5-hour charge, so multi-day riders will be charging more often.
• Sunffice Open Ear — biggest strength: 15 hours of music, 20 hours of calls and 70 hours of standby, which covers even very long rides and double-session training days.
• Sunffice Open Ear — biggest trade-off: the water resistance is described only as IPX and the manufacturer explicitly says it is not suitable for swimming, so it is a sweat-and-weather headphone, not a pool headphone.
• Who each is for: RELAXYO for swimmers and anyone who wants music without a phone nearby; Sunffice for cyclists, runners and gym-goers who want all-day battery and don't need to submerge their headphones.
The RELAXYO X26 is built around one idea: keep the music going when your phone can't follow you. The IP68 rating is the headline. It's the kind of sealing that shrugs off sweat, rain, surf spray and full immersion, and the brand notes it can be worn under a swim cap or goggles. That single spec moves it into a category most open-ear sport headphones never enter.
The second pillar is the 32GB of onboard memory — roughly 7,000 songs' worth. That matters because Bluetooth simply doesn't transmit through water. RELAXYO solves this with a dual-mode design: double-press the power button to switch between Bluetooth 5.4 and MP3 mode, load tracks over the magnetic charging cable from a computer, and swim with nothing but the headphones on your head. Bluetooth 5.4 also gives a claimed 10-metre-plus range in open space, and the three-button layout handles power, track skip, volume and voice-assistant wake-up without you needing to look.
Sunffice Open Ear: Who It's For
The Sunffice Open Ear headset takes the opposite approach: it doesn't try to go underwater, it tries to outlast your longest day. The numbers tell the story — 15 hours of continuous music, 20 hours of calls and 70 hours of standby on a single charge. For a cyclist doing weekend centuries, a runner stacking double sessions, or someone who simply forgets to charge things, that's the whole point. You plug in a Type-C cable, and you're set for days of normal use.
It uses a bone conduction driver too, so your ear canals stay open and you keep hearing traffic, other riders and your surroundings — the safety argument that makes open-ear designs popular on the road. The memory titanium alloy neckband twists to fit different head shapes, and the hook-style earpieces sit outside the ear rather than inside it. Bluetooth 5.2 handles the connection with low latency, and Sunffice advertises lossless HiFi stereo tuning with bass delivered through the cheekbones. There's also a multifunctional button for play/pause, calls and summoning Siri.
Here's the part that matters for buyers: Sunffice describes the water resistance as IPX and states plainly that the headphones are not suitable for swimming. The Type-C port has a waterproof cover, and the set is described as sweat-proof and water-resistant enough for intense exercise and bad weather — but that's a different promise from IP68 submersion. Buy it for cycling, running, gym work and commuting. Don't buy it expecting to swim laps.
Side-by-Side: Which Should You Choose?
• Best for swimming → RELAXYO Bone Conduction Swimming. IP68 plus MP3 mode is the only way either pair works underwater.
• Best for phone-free listening → RELAXYO Bone Conduction Swimming. 32GB of storage holds roughly 7,000 songs without a paired device.
• Best for long rides and all-day wear → Sunffice Open Ear. The neckband design and 15-hour runtime suit multi-hour cycling and commuting.
• Best for underwater reliability → RELAXYO Bone Conduction Swimming. Sunffice explicitly rules out swimming.
• Best for the newest wireless tech → RELAXYO Bone Conduction Swimming. Bluetooth 5.4 versus Bluetooth 5.2 on the Sunffice.
• Best for quick top-ups → RELAXYO Bone Conduction Swimming. A 1.5-hour charge gets you back to full; Sunffice doesn't state a charge time.
• Best for call-heavy days → Sunffice Open Ear. Sunffice quotes 20 hours of call time with a built-in mic and voice-assistant control.
• Best for noise blocking → neither, really. Both are open-ear by design, so you hear the world. Sunffice lists active noise cancellation as a control feature, but open-ear fit means isolation is limited — the trade-off you accept for safety.
If I were buying one pair for cycling specifically, I'd take the Sunffice Open Ear. Fifteen hours of music, 70 hours of standby, a flexible neckband and a lower Bluetooth generation that still handles stable, low-latency audio — that's the combination that survives a long ride week after week without a charger in your pocket. In my opinion, RELAXYO wins outright if your training includes water, because IP68 and 32GB of built-in music are capabilities Sunffice simply doesn't offer. If your rides never touch a pool, the battery advantage decides it.
It depends entirely on water. If you swim, surf or train in wet conditions, RELAXYO's IP68 rating and 32GB MP3 mode are features Sunffice doesn't match — Sunffice states it isn't suitable for swimming. If you don't get your headphones wet, Sunffice's 15-hour battery is the more useful spec. You can check the current price on Amazon for both before deciding.
Yes. Sunffice describes the set as sweat-proof and water-resistant for intense exercise and extreme weather, and the Type-C port has a waterproof cover. Just don't submerge them — that's outside what the IPX rating and the manufacturer's own note promise.
Sunffice, clearly. It quotes 15 hours of music, 20 hours of calls and 70 hours of standby. RELAXYO quotes up to 7 hours of music from a 1.5-hour charge. For long cycling days, Sunffice gives you roughly double the listening time.
Only the RELAXYO does. Its 32GB of built-in storage lets you load songs from a computer over the magnetic charging cable and play them in MP3 mode with no device connected. Sunffice relies on a Bluetooth connection, so you need a paired phone, watch or tablet.
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