We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-30 · 6 min read · Independent comparison
If you want a cycling-focused open-ear headphone with maximum visibility and long battery life, choose HAKII Light 2; if you need a swim-proof bone conduction headphone with built-in music storage, choose LOBKIN Bone Conduction Swimming.
• HAKII Light 2 — biggest strength: a 180° Ultra-Bright Beacon String with three lighting modes, plus 16 hours of playtime and a 26g air-conduction design that never enters your ear.
• HAKII Light 2 — biggest trade-off: IPX5 only, so rain and sweat are fine but full submersion is not.
• LOBKIN Bone Conduction Swimming — biggest strength: IP68 waterproofing plus 32GB of onboard memory, so you can swim with music and leave your phone behind.
• LOBKIN Bone Conduction Swimming — biggest trade-off: 10 hours of playtime and no lighting at all, which matters less underwater but a lot more on a dark road.
• Who each pick is for: HAKII Light 2 for cyclists, runners and night-time outdoor athletes; LOBKIN for swimmers, surfers and anyone who trains in and around water.
The HAKII Light 2 is built around one problem most open-ear headphones ignore: being seen. The integrated 180° Ultra-Bright Beacon String runs along the frame and offers three lighting modes, which is exactly the kind of feature a cyclist notices on a commute home after sunset. Pair that with the open-ear fit — no insertion, no pressure, ears fully open to traffic, bells and voices — and you have a headphone designed for roads, paths and shared spaces rather than pools.
The audio side is air conduction, not bone conduction. HAKII uses 16mm BassBoost dynamic drivers with a 22-ohm impedance, 135dB sensitivity and a 20kHz frequency response. In plain terms, those are big drivers tuned for low-end weight, and air conduction avoids the clamping pressure and tragus vibration that bone conduction relies on. Add Bluetooth 6.0, dual AI noise-cancelling microphones, an IPX5 rating and 16 hours of playback from a one-hour charge, and it covers long rides, rainy runs and even work calls reasonably well. At 26g with a flexible titanium frame and soft silicone, it's light enough to forget you're wearing it.
Buy it if: you ride, run or hike outdoors, you care about being visible at night, you want big bass and long battery life, and you'd rather not have anything inside your ear canal.
LOBKIN Bone Conduction Swimming: Who It's For
The LOBKIN X21 solves a completely different problem: how to listen to music with your head underwater and no phone nearby. The IP68 rating is the headline — it's engineered for 2+ hours at depths up to 10ft — and the 32GB of onboard memory holds thousands of tracks. That combination is the whole point. Bluetooth doesn't travel through water, so you switch the headphone into MP3 mode and it plays independently, no device required. That's a genuinely different use case from anything the HAKII offers.
It's a bone conduction design, which means sound travels through vibrations against your cheekbone and your ear canal stays completely open. LOBKIN pairs that with a flexible titanium alloy frame, a skin-friendly soft coating and memory foam ear tips, at 29 grams. Bluetooth 5.4 handles wireless listening on land with low latency, there's a noise-cancelling microphone for calls, and magnetic charging tops it up in about two hours for roughly 10 hours of playback. The frequency response reaches 20kHz, and the 8-ohm impedance and 90dB sensitivity reflect the lower-power bone conduction driver inside.
Buy it if: you swim laps, surf, or do watersports, you want music without carrying a phone, and you split your training between water and land.
Skip it if: you mostly ride at night or want headphone lighting for visibility. There's no lighting here, battery life is shorter than the HAKII's, and bone conduction won't give you the bass weight a 16mm dynamic driver will.
• Best for swimming and watersports → LOBKIN Bone Conduction Swimming. IP68 and 32GB of MP3 storage are the only way this comparison goes underwater.
• Best for night-time cycling and road visibility → HAKII Light 2. Three lighting modes along a 180° beacon string is a safety feature you simply won't find on the LOBKIN.
• Best for battery life → HAKII Light 2. 16 hours versus 10, and it recharges in one hour instead of two.
• Best for listening without a phone → LOBKIN Bone Conduction Swimming. 32GB of onboard memory holds thousands of tracks; the HAKII relies entirely on a Bluetooth connection.
• Best for bass-heavy workout sound → HAKII Light 2. 16mm BassBoost dynamic drivers with 135dB sensitivity are tuned for low-end punch that bone conduction can't match.
• Best for wireless range and everyday pairing → HAKII Light 2. Bluetooth 6.0 with a 10-metre rated range is a newer generation than the LOBKIN's Bluetooth 5.4.
• Best for all-day wear comfort → close call. 26g versus 29g is nearly a wash; both use titanium frames and soft coatings, and both are designed to avoid ear-canal pressure.
• Best for rain and heavy sweat → HAKII Light 2 is fine, but LOBKIN is safer. IPX5 covers splashes; IP68 is the more protective rating if you're regularly soaked.
If I had to pick one, I'd buy the HAKII Light 2 for cycling and general outdoor training. In my opinion, the combination of the beacon lighting, 16 hours of playback, Bluetooth 6.0 and 16mm bass drivers makes it the more useful everyday headphone for the way most people actually train — on roads, paths and trails where being seen matters more than being submerged. The LOBKIN is the better product for exactly one job, and it does that job brilliantly: swimming with music and no phone. If you swim, buy the LOBKIN. If you ride, buy the HAKII.
FAQ
Yes — it carries an IP68 rating and is engineered for 2+ hours at depths up to 10ft. Remember to switch it into MP3 mode underwater, since Bluetooth signals don't travel through water.
No. Its IPX5 rating protects against sweat and water splashes, which covers rain and hard workouts, but it isn't built for submersion. For pool or open-water swimming, the LOBKIN is the correct choice.
Not for swimming or offline listening. The 32GB of built-in memory stores thousands of tracks so it plays independently. You'd only need a phone if you want Bluetooth streaming on land.
For me, the HAKII Light 2. The three-mode beacon string, 16-hour battery and newer Bluetooth 6.0 suit long rides and low-light commutes better. The LOBKIN can handle cycling as an everyday activity, but it has no lighting and less playtime. If you're weighing cost, check the current price on Amazon for both before deciding.
As an Amazon Associate I earn from qualifying purchases.
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
When you buy through links on this page, we may earn a commission from qualifying purchases at no extra cost to you.
Amazon and the Amazon logo are trademarks of Amazon or its affiliates. This site is an independent third-party review and is not affiliated with, endorsed by, or sponsored by Amazon or the product brands mentioned.
See also: Redragon H510 vs Audio-Technica ATH-GL3BK, HomeSpot Audio Adapter vs UGREEN Transmitter Receiver, SULWZM Hearing Protection Ear vs ZHENYEMEI Sleep Mask, Waneni Kids Headphones Bulk vs Generic Kids: Teen Headphones