We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-05 · 6 min read · Independent comparison
If you want a lightweight, all-day clip-on pair that disappears on your ears and carries its own charging case for commuting, choose Kinglucky i21; if you need a rugged, fully waterproof headset with built-in MP3 storage for swimming and sweaty training, choose Roujune Bone Conduction Headphones.
• Kinglucky i21 — biggest strength: a genuinely featherweight open-ear clip design (4.7 g per bud) with a charging case that stretches total listening to 45 hours, which is exactly what a commuter wants.
• Kinglucky i21 — biggest trade-off: only IPX4 water resistance and no built-in music storage, so it is fine in rain and sweat but not for swimming.
• Roujune Bone Conduction Headphones — biggest strength: IPX8 waterproofing plus 32 GB of onboard memory and an MP3 mode, so you can swim without a phone.
• Roujune Bone Conduction Headphones — biggest trade-off: no charging case is listed, so you are working with the headset's own 8 hours per charge, and the headband-style open-ear fit is more noticeable than a clip.
• Who each pick is for: Kinglucky i21 for glasses wearers, small ears and commuters who want a case in their bag; Roujune for swimmers, gym-goers and anyone who wants music with no phone nearby.
The Kinglucky i21 is an open-ear clip-on earbud, and the whole design revolves around not putting anything inside your ear canal. Each bud weighs 4.7 g and hooks over the ear rather than pressing into it. If you wear glasses, that matters — the clip sits around the ear instead of competing with your frames, and there is no in-ear pressure building up over a long day. For small ears, the absence of a silicone tip to seat correctly removes the usual fit headache entirely.
Where this thing earns its place is the charging case. You get 6 hours of continuous playback per charge and up to 45 hours total with the case, plus 90 hours of standby. For commuting specifically, that combination is the point: drop the buds in the case on the train, top them up without hunting for a cable, and never think about battery again during the week. Bluetooth 5.3 covers the connection side with a stated 30-meter range, and the audio driver is listed as a bone conduction driver with a 20 Hz – 20,000 Hz frequency range and 16 ohm impedance.
What it is not: a swimming headset. IPX4 with a nano hydrophobic coating handles rain and sweat, which is plenty for a run or a wet commute, but it is not submersible. There is also no onboard storage — your music comes from your phone over Bluetooth, full stop. In my opinion, this is the better pick if your priority is a comfortable, near-invisible open-ear bud for daily commuting, running and glasses wearers. Skip it if you swim laps or want to leave your phone behind.
The Roujune X20 is built around a different idea: take the phone out of the equation. It carries 32 GB of internal memory and an MP3 mode, which is why the manufacturer's own guidance tells you to switch out of Bluetooth before you get in the water — Bluetooth simply does not travel underwater. So the workflow is: load your files (MP3, WMA, FLAC, APE or WAV), double-press the power button to swap between Bluetooth and MP3 mode, and swim with nothing but the headset on your head. That is a genuinely different product category from a commuting earbud.
The IPX8 rating is the headline. That is full waterproofing rather than splash resistance, and combined with the open-ear bone conduction driver (20 Hz – 20,000 Hz) it means you keep your ear canals open and still hear your surroundings while you train. Battery life is 8 hours per charge, and there is a 2-year manufacturer warranty listed. Bluetooth 5.4 handles the wireless side when you are not in the pool. The enclosure is metal, the colour is Apricot, and it is a headband-style open-ear fit rather than a clip.
The trade-offs are real. There is no charging case in the listed specs, so 8 hours is what you get and then you recharge. The headband shape is more visible and more present on your head than a clip-on bud, and for a crowded commute I would not call it the most discreet option. In my opinion, this is the pick for swimmers, heavy sweaters, and anyone who wants to run or ride phone-free.
Side-by-Side: Which Should You Choose?
• Best for water → Roujune Bone Conduction Headphones. IPX8 versus IPX4 is not a small gap; one is submersible, the other is rain-and-sweat resistant.
• Best for phone-free listening → Roujune Bone Conduction Headphones. 32 GB of onboard storage and MP3 mode mean no phone required at all.
• Best for glasses wearers and small ears → Kinglucky i21. The clip-on open-ear shape avoids both the in-ear seal problem and frame interference.
• Best for all-day wear comfort → Kinglucky i21. At 4.7 g per bud with no ear-canal insertion, it is the lighter daily companion.
• Best for swimming specifically → Roujune Bone Conduction Headphones. This is the entire reason the MP3 mode exists.
• Best for a commuting bag → Kinglucky i21. Charging case, compact clip design, Bluetooth 5.3 with a 30-meter range.
• Best for workout durability → Roujune Bone Conduction Headphones. IPX8 and a metal enclosure suit hard training.
For commuting, I would buy the Kinglucky i21. The charging case, the 45-hour total playtime and the 4.7 g clip-on fit are exactly what a daily train or bus journey rewards, and glasses wearers and small-eared listeners get a fit that just works without fiddling. The Roujune X20 is the better product for a swimmer — IPX8 and 32 GB of MP3 storage are things the i21 simply does not offer. But if your main use is getting to work and back with music in your ears and nothing to charge every night, the i21 is the one I would pick. Check the current price on Amazon before you commit, since that is the one thing specs cannot tell you.
Both list a bone conduction driver with a 20 Hz – 20,000 Hz range, and both are open-ear designs. The Kinglucky i21 uses an ear-clip shape, while the Roujune X20 uses a headband-style open-ear fit.
No. It is rated IPX4 with a nano hydrophobic coating, which covers rain and sweat but not submersion. For swimming you need the Roujune X20 and its IPX8 rating.
It depends how you measure it. The Kinglucky i21 gives 6 hours per charge but up to 45 hours with its charging case. The Roujune X20 gives 8 hours per charge with no case listed.
No. The Roujune X20 has 32 GB of internal memory and an MP3 mode, so you can load MP3, WMA, FLAC, APE or WAV files and listen without Bluetooth. The Kinglucky i21 requires a Bluetooth connection.
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