How We Research
Updated: 2026-09-30 · 7 min read · Independent comparison
If you want a purpose-built replacement cable for Shokz bone conduction headphones that adds fast charging protection, choose gudxfj 2; if you need to listen to wired headphones and fast charge a USB-C phone at the same time, choose Kemsky USB C Double.
• gudxfj 2 — biggest strength: Two magnetic-tip charging cables in one pack (one USB-A, one USB-C), each 3.3 ft, made specifically for Shokz and AfterShokz bone conduction models — with built-in power protection for safer, faster, more stable charging.
• gudxfj 2 — biggest trade-off: It only charges Shokz-style bone conduction headphones. It does not play audio and it will not fit any other brand or connector type.
• Kemsky USB C Double — biggest strength: A 3-in-1 USB-C splitter that lets you plug in dual 3.5mm jacks while pulling PD 60W fast charging, with a DAC chip rated up to 24bit/96kHz for Hi-Fi audio.
• Kemsky USB C Double — biggest trade-off: It needs a USB-C device to plug into, and the audio side is analog 3.5mm only — no magnetic charging, no bone conduction headphone support.
• Who each pick is for: gudxfj 2 for Shokz OpenRun/OpenRun Pro/Aeropex/OpenComm owners who want a spare or replacement charge cable; Kemsky USB C Double for phone, tablet, laptop or handheld-console users who want to charge and listen through one port.
The gudxfj 2 is a two-pack of replacement charging cables built around a magnetic charging module. If you own Shokz or AfterShokz bone conduction headphones — Aeropex AS800, OpenComm ASC100SG, OpenRun Pro, OpenRun, OpenRun Mini, or OpenRun Pro Mini — this is the cable family you already know. The magnet snaps into place, so you are not hunting for a tiny port in the dark or fumbling with a Micro-USB style connector that never quite seats right.
What it does best is give you redundancy and flexibility in one purchase. You get two 3.3 ft black cables, one terminating in a USB-A plug and one in USB-C, so you can leave one at your desk and one in a bag, or use the USB-A version with a wall adapter and the USB-C version with a laptop or power bank. The construction is ABS and PVC over copper wire, which the manufacturer pairs with a chip for short-circuit protection and stable current delivery. That is the "fast charge" story here: not a wattage number, but a clean, protected connection so your headphones top up safely and predictably.
The 3.3 ft length is a genuinely practical detail. It is long enough to reach from a floor outlet or a car adapter to a headset on your head, and short enough to coil into a pocket without turning into a knot — the cable is also listed as tangle-free. At 34 g for the set, it disappears in a bag.
Who should skip it: anyone who does not own a Shokz or AfterShokz bone conduction model. There is no audio passthrough, no 3.5mm jack, and no universal fit. This is a single-purpose accessory, and that is exactly the point. If you want a spare cable before yours fails — or you have lost the original — this is a sensible, low-drama replacement. Check your headphone model against the compatibility list before ordering, because the magnetic tip pattern is specific.
The Kemsky USB C Double solves a different, very modern problem: your phone has one USB-C port, and you need it for two things at once. This 3-in-1 adapter splits that port into dual 3.5mm jacks plus pass-through PD 60W charging, so you can listen to music, take calls, game, or watch video while the battery keeps climbing instead of draining.
The audio side is where Kemsky puts real effort. The built-in smart DAC chip supports up to 24bit/96kHz decoding — double the resolution class of the common 16bit/48kHz adapters — and the brand pairs that with noise reduction for a cleaner, higher-fidelity signal. If you have wired headphones or IEMs you actually like, this is the piece that lets you keep using them on a phone that never had a headphone jack.
The charging side is the headline for anyone searching "fast charge headphones." PD 60W is a serious power ceiling for a dongle, with a dedicated charging chip that negotiates the voltage and current your specific device wants, which is what keeps things stable and safe rather than just fast. Plug and play — no drivers, no software, no setup ritual.
Compatibility is broad: iPhone 17/16/15 families, Galaxy S23 through S26 Ultra, Pixel 6 through 10 series, iPad and iPad Pro/Air, MacBook Pro/Air 2024, XPS 13/15/17, Surface Book 3, Steam Deck, Switch 2 and more. The housing is ABS, corrosion-resistant, and compact enough to live on a keyring or in a pocket.
Side-by-Side: Which Should You Choose?
• Best for Shokz/AfterShokz owners → gudxfj 2. It is the only one of the two designed for magnetic-tip bone conduction charging.
• Best for charging while listening → Kemsky USB C Double. Dual 3.5mm jacks plus PD 60W pass-through is a combination gudxfj cannot offer.
• Best for audio quality → Kemsky USB C Double. The DAC chip's 24bit/96kHz ceiling is a concrete, measurable step above typical 16bit/48kHz adapters.
• Best for redundancy and travel → gudxfj 2. Two cables, two connector types (USB-A and USB-C), 3.3 ft each, 34 g total.
• Best for multi-device households → Kemsky USB C Double. One adapter covers phones, tablets, laptops, Steam Deck and Switch 2.
• Best for a simple, single-purpose fix → gudxfj 2. No drivers, no negotiation, just snap and charge.
• Best for wired-headphone users on jackless phones → Kemsky USB C Double. That is the exact scenario it was built for.
• Skip gudxfj 2 if → you do not own a compatible Shokz/AfterShokz model.
• Skip Kemsky USB C Double if → your headphones charge magnetically or you need a replacement charge cable, not an audio splitter.
In my opinion, the right pick comes down to which problem you actually have. If you own Shokz or AfterShokz bone conduction headphones, I would buy the gudxfj 2 — two protected magnetic cables in one pack is the practical, no-fuss answer, and it directly targets the fast-charge experience those headsets are known for. If instead your daily frustration is a phone with one port and a pair of wired headphones you refuse to give up, I would buy the Kemsky USB C Double. The PD 60W fast charging plus 24bit/96kHz DAC is the more capable piece of hardware overall. Different jobs, both done well.
FAQ
how to charge headphones faster
how to charge headphones
For Shokz and AfterShokz bone conduction models, connect the gudxfj 2 magnetic tip to the headphone, then plug the USB-A or USB-C end into your power source. For wired 3.5mm headphones used with a jackless phone, the Kemsky adapter passes charging through its USB-C port while the headphones plug into the audio jack.
how to fast charge bose headphones
Neither product in this comparison is specified for Bose headphones. gudxfj 2 is built for Shokz and AfterShokz magnetic charging, and Kemsky USB C Double is a USB-C splitter for 3.5mm audio plus PD 60W power. Check your headphone's charging interface before buying either.
is fast charging bad for headphones
Not inherently. gudxfj 2 and Kemsky USB C Double both describe protection circuitry — short-circuit protection and a charging chip that regulates voltage and current — which is the part that matters for safety. Always use a compatible charger and cable for your specific headphone model.
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