| Wokyis M5 dock bundled Thunderbolt 5 cable, 0.5 m (Sumitomo silicon, 80 Gbps variant of PID 0x0714) | `0x20C2` | `0x0714` | `0x460A2644` | Sumitomo Electric Ind., Ltd., Optical Comm. R&D Lab | none | USB4 Gen 4 (80 Gbps, Thunderbolt 5 class) | 5 A / 50 V (240 W) | passive | [#405](https://github.com/darrylmorley/whatcable/issues/405) |

| Cable Matters active Thunderbolt 5 cable, 2 m | `0x2B1D` | `0x192F` | `0x426A5E5C` | Lintes Technology Co., Ltd. | none | USB4 Gen 4 (80 Gbps, Thunderbolt 5 class) | 5 A / 50 V (240 W) | active | [#406](https://github.com/darrylmorley/whatcable/issues/406) |

| OWC Thunderbolt 5 cable, 12 in (Lintes silicon) | `0x2B1D` | `0x153E` | `0x110A2644` | Lintes Technology Co., Ltd. | `0x5FD` | USB4 Gen 4 (80 Gbps, Thunderbolt 5 class) | 5 A / 50 V (240 W) | passive | [#408](https://github.com/darrylmorley/whatcable/issues/408) |

Sorted by VID. The zeroed-fingerprint entry is parked at the bottom because it

is identity-less.

<p>This is the part nobody talks about. A USB-C cable in a Thunderbolt port is still a USB-C cable. The port will negotiate down to whatever the cable supports. You can have a TB5 port and a 40 Gbps device and still get USB 3.2 speeds because the cable in the middle is a 20 Gbps cable that came with a hard drive five years ago.</p>

<p>Every USB-C cable rated above 60W and above USB 2.0 speeds contains an e-marker chip. The chip declares what the cable can carry: max current, max voltage, max data rate. macOS reads this chip every time you connect a cable. It just doesn't show you what it reads.</p>

<p><a href="https://www.whatcable.uk/">WhatCable</a> reads the e-marker and shows you what the cable is. Not what you hoped it was, not what the box claimed, what the cable itself is telling the Mac. If you've ever wondered whether the "Thunderbolt cable" you bought online is actually Thunderbolt, this is how you check. You can also see how your cable rates against known references in the <a href="https://www.whatcable.uk/cables">cables database</a>.</p>

<p><img src="https://images.whatcable.uk/1779375774954-whatcable-screenshot-usb4-cable-readout.webp" alt="WhatCable showing a USB-C cable identified as USB4 Gen 3, 40 Gbps, Thunderbolt 4 class, rated for 5A at 50V, with a confirmation that the connected 10 Gbps drive is running at full device speed" title="WhatCable identifying a USB4 cable in the menu bar"></p>

<h2>Compatibility, both directions</h2>

<p><strong>USB-C device into a Thunderbolt port:</strong> works, at USB speeds. The TB port has full USB-C compatibility built in. Plug in a phone, a basic USB hub, or a regular external drive and it'll run at whatever the device supports.</p>

<p>This is the part nobody talks about. A USB-C cable in a Thunderbolt port is still a USB-C cable. The port will negotiate down to whatever the cable supports. You can have a TB5 port and a 40 Gbps device and still get USB 3.2 speeds because the cable in the middle is a 20 Gbps cable that came with a hard drive five years ago.</p>

<p>Every USB-C cable rated above 60W and above USB 2.0 speeds contains an e-marker chip. The chip declares what the cable can carry: max current, max voltage, max data rate. macOS reads this chip every time you connect a cable. It just doesn't show you what it reads.</p>

<p><a href="/">WhatCable</a> reads the e-marker and shows you what the cable is. Not what you hoped it was, not what the box claimed, what the cable itself is telling the Mac. If you've ever wondered whether the &quot;Thunderbolt cable&quot; you bought online is actually Thunderbolt, this is how you check. You can also see how your cable rates against known references in the <a href="/cables">cables database</a>.</p>

<p><img src="https://images.whatcable.uk/1779375774954-whatcable-screenshot-usb4-cable-readout.webp" alt="WhatCable showing a USB-C cable identified as USB4 Gen 3, 40 Gbps, Thunderbolt 4 class, rated for 5A at 50V, with a confirmation that the connected 10 Gbps drive is running at full device speed" title="WhatCable identifying a USB4 cable in the menu bar"></p>

<h2>Compatibility, both directions</h2>

<p><strong>USB-C device into a Thunderbolt port:</strong> works, at USB speeds. The TB port has full USB-C compatibility built in. Plug in a phone, a basic USB hub, or a regular external drive and it'll run at whatever the device supports.</p>

"name": "WhatCable cable fingerprint database",

"description": "Crowd-sourced USB-C cable e-marker fingerprints reported via WhatCable. Each entry records the cable's USB-IF VID/PID, cable VDO bitfield, advertised speed, power rating, and a link to the original report.",

"url": "https://www.whatcable.uk/cables",

"keywords": [

"USB-C", "USB4", "Thunderbolt", "Thunderbolt 5", "e-marker",

"USB Power Delivery", "USB-C cable database", "cable VDO", "USB-IF VID"

<div class="wrap-cables">

<h1>USB-C Cable Database</h1>

<p>

Every USB-C cable with an e-marker chip reports an identity when you

<td class="col-type">passive</td>

<td class="col-source"><a href="https://github.com/darrylmorley/whatcable/issues/408">#408</a></td>

</tr>

</tbody>

</div>

"vid" : "0x34BD",

"xid" : "0x10536"

},

{

"brand" : "Silkland USB4 80 Gbps cable 3.3 ft, Amazon",

"cableVDO" : "0x000A2644",

<div class="faq-item"><h3>Is it really free?</h3><p>Yes. The WhatCable app is free and open source under the MIT licence. No ads, no tracking. WhatCable Pro (£9.99, optional) adds advanced diagnostics for power users. <a href="/pro" style="color: var(--accent);">See what's included.</a></p></div>

<div class="faq-item"><h3>What does WhatCable Pro add?</h3><p>Pro unlocks 16 advanced features including cable history (named cables with a recorded timeline), live power metering, Negotiation and Display Diagnostics, port health counters, PD contract inspection, and raw VDO identity. One-time £9.99, no subscription, works on up to 2 Macs. <a href="/pro" style="color: var(--accent);">See full features and comparison.</a></p></div>

<div class="faq-item"><h3>Does it phone home or collect data?</h3><p>No analytics, no telemetry, and nothing about you or your cables ever leaves your Mac. The one routine network call is a version check against the public GitHub Releases API, roughly every 6 hours. Diagnostic data only goes anywhere if you explicitly choose to contribute it. Check the source on GitHub if you want to verify.</p></div>

<div class="faq-item"><h3>Why does my cable show no e-marker data?</h3><p>Two reasons. Either the cable has no e-marker chip (cheap USB 2.0 cables and many cables rated at 3A or below don't have one), or it has a chip but macOS hasn't read it. macOS only asks a cable to identify itself when the connection needs it: a charge drawing more than 3A (a 5A cable on a high-wattage charger), or a Thunderbolt / USB4 link. Plug a marked cable into a low-power charger or a plain data connection and macOS may never query it, so there's nothing for WhatCable to show. To force the read, connect the cable to a high-wattage charger or a Thunderbolt device.</p></div>

<div class="faq-item"><h3>Can it tell me if a cable is fake?</h3><p>Not definitively. The trust signals feature flags values that look unusual against the USB-PD spec, like a zero vendor ID or reserved bit patterns. A flag means "worth checking," not "definitely counterfeit."</p></div>

<div class="faq-item"><h3>What languages is WhatCable available in?</h3><p>19, and the diagnostic verdicts are translated too, not just the menus: Armenian, Brazilian Portuguese, Dutch, English, French, German, Hindi, Italian, Japanese, Korean, Latvian, Norwegian, Polish, Russian, Simplified Chinese, Spanish, Traditional Chinese, Turkish, and Ukrainian. WhatCable follows your Mac's language by default, or you can pick one in Settings. Translations are community-refinable, so if something reads oddly in your language, <a href="https://github.com/darrylmorley/whatcable/issues" style="color: var(--accent);">open an issue</a> and we'll fix it.</p></div>

<table class="cables">

<thead>

<tr>

<td class="col-type">passive</td>

<td class="col-source"><a href="https://github.com/darrylmorley/whatcable/issues/408">#408</a></td>

</tr>

</tbody>

</table>

[WhatCable](/) reads the e-marker and shows you what the cable is. Not what you hoped it was, not what the box claimed, what the cable itself is telling the Mac. If you've ever wondered whether the "Thunderbolt cable" you bought online is actually Thunderbolt, this is how you check. You can also see how your cable rates against known references in the [cables database](/cables).