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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-23 · 7 min read · Independent comparison
• CASCHO Ear buds — biggest strength: A 650mAh charging case that pushes total playtime to 60 hours, plus a 14.5mm graphene driver that puts real low-end into the mix.
• CASCHO Ear buds — biggest trade-off: No active noise cancellation and the manufacturer explicitly warns against showering or swimming despite the IPX7 rating. Sealing depends on you picking the right eartips.
• Sunffice Open Ear — biggest strength: Bone-conduction sound that leaves your ear canal completely open, so you hear cars, cyclists and coworkers while music plays through your cheekbones.
• Sunffice Open Ear — biggest trade-off: 15 hours total battery with no charging case to top it up, and a bone-conduction driver that simply cannot deliver the bass depth of a sealed in-ear.
• CASCHO is for you if you want long solo sessions, gym work, calls and heavy bass without thinking about the charger.
• Sunffice is for you if you run or ride near traffic, or you've never found an in-ear that stays comfortable past an hour.
The CASCHO BX17 is built around a very specific idea: you should be able to leave the house on Monday and not worry about the charger until the weekend. The case packs a 650mAh battery, and combined with the earbuds themselves you're looking at up to 60 hours of listening. A single earbud alone gets roughly 10 hours. The case also has a digital display that shows the remaining charge in 25% steps for each side, which sounds like a small thing until you've owned a case with a single blinking light and no idea whether you have an hour or a day left.
On audio, CASCHO uses a 14.5mm graphene diaphragm — a noticeably large driver for this category. The spec sheet lists a 20Hz–2000Hz frequency range, 32 ohm impedance and 103dB sensitivity. In practical terms, that combination points to a warm, bass-forward signature that's easy to drive from any phone. There's a built-in mic for calls. Just be realistic: there is no active noise cancellation here, and CASCHO's own guidance says that if the bass feels thin, you should swap eartips until you get a proper seal. That's an honest admission that the seal is doing the heavy lifting.
Buy it if you want maximum runtime, a locked-in fit, tactile controls and bass you can feel. Skip it if you need to hear your surroundings, want ANC for flights and trains, or plan to swim.
Sunffice Open Ear: Who It's For
The Sunffice is a different animal entirely, and the spec sheet makes that clear from the first line. This is a bone-conduction headphone: the driver sits against your cheekbone and transmits vibration through bone to your inner ear, leaving the ear canal completely open. Nothing goes inside your ear. For anyone who has spent years fighting eartips that slip, itch or ache after 45 minutes, that's the entire pitch, and it's a legitimate one.
The consequence is safety and awareness. Sunffice's own framing is that you keep perceiving your surroundings while listening — traffic, a passing cyclist, a coach shouting splits, a colleague asking a question. If you run on roads or ride a bike, that isn't a nice-to-have, it's the reason to buy this product over anything with a seal. It also means no ear fatigue, which is why Sunffice positions it as an all-day listening tool.
Battery is 15 hours of music, 20 hours of calls and 70 hours of standby, charged over USB-C with a waterproof cover over the port. There's no charging case — the headphone itself is the whole package, and you charge it directly. The frame is memory titanium alloy, which twists to fit different head shapes and holds its form. Bluetooth 5.2 handles a stable, low-latency connection with a 10m range, and the listed frequency range is a wide 20Hz–20,000Hz. Sunffice also lists active noise cancellation in the controls data, though with an open-ear bone-conduction design the practical effect is limited — you're not blocking out a plane cabin with these. Controls are a single multi-function push button for play/pause, Siri and calls.
One caveat worth stating plainly: the water resistance is described as sweat-proof and water-resistant, and the listing itself notes it's not suitable for swimming. That's a lesser rating than the CASCHO's IPX7 claim, so treat this as rain-and-sweat protection, not submersion.
Buy it if you prioritize situational awareness, comfort over long stretches, and a fit that adapts to your head. Skip it if you want deep bass, a charging case, or isolation from background noise.
• Best for total battery life → CASCHO Ear buds. 60 hours with the case versus 15 hours on the Sunffice.
• Best for situational awareness and road safety → Sunffice Open Ear. Open ear canal, by design.
• Best for bass and punch → CASCHO Ear buds. A 14.5mm graphene dynamic driver against a bone-conduction driver isn't a fair fight on low end.
• Best for long-session comfort → Sunffice Open Ear. Nothing enters your ear, so there's no pressure point to build up.
• Best for heavy sweat and rain → CASCHO Ear buds. IPX7 with a rigid seam design is the stronger claim of the two.
• Best for gloved or wet-hand control → CASCHO Ear buds. Physical multifunction buttons with volume control beat hunting for a single push button.
• Best for sharing or one-ear use → CASCHO Ear buds. Stereo/mono switching lets you hand one earbud to someone else.
• Best for adapting to different head sizes → Sunffice Open Ear. The memory titanium alloy band twists to fit.
• Best if you hate charging cases → Sunffice Open Ear. One USB-C cable, no case to keep track of.
In my opinion, the CASCHO Ear buds win this comparison for most people, and the reason is simple arithmetic: 60 hours versus 15, a charging case with a real battery readout, a much larger driver, IPX7, and buttons you can operate blind. If you're buying one pair of workout headphones and you mostly train indoors or in open spaces, that's the pick I'd make. The Sunffice Open Ear only wins on one axis, but it's an important axis — if you run or ride near traffic, or in-ears have never stayed comfortable, the open-ear design is worth more than every spec advantage CASCHO holds. Check the current price on Amazon for both before you commit, because that's the one variable that can flip this call.
CASCHO, by a wide margin. It offers up to 60 hours total with the charging case and about 10 hours per single earbud. The Sunffice gives you 15 hours of music, 20 hours of calls and 70 hours of standby, with no case to extend it.
Sunffice lists active noise cancellation in its control data, but this is a bone-conduction open-ear design, so your ear canal stays open and ambient sound reaches you regardless. Don't expect the isolation a sealed in-ear provides.
No. CASCHO states you can use its earbuds while exercising but not while swimming or bathing, despite the IPX7 rating. Sunffice describes its headphones as sweat-proof and water-resistant and explicitly notes they aren't suitable for swimming.
The Sunffice Open Ear, in my opinion. Its whole design premise is no earplugs and no ear fatigue, and the memory titanium alloy band adjusts to your head. CASCHO relies on silicone earhooks and a sealed eartip, which is secure but puts pressure inside the ear over long sessions.
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