3 5mm Extension Cable: Untangling the Notation
Spacing, punctuation and unit conventions make audio connector searches inconsistent. The same product is listed as 3.5mm, 3 5mm, 3.5 mm and occasionally as 35mm, which is a completely different object.
Quick Answer
3.5mm, 3 5mm and 3.5 mm all describe the same 3.5 millimetre mini jack, written with different spacing because search engines and marketplaces strip punctuation. 35mm does not. That refers to a 35 millimetre film format. When ordering, confirm the size in millimetres and check the pole count rather than trusting the listing format.
Notation Compared
| Written as | Means | Correct |
|---|---|---|
| 3.5mm | 3.5 millimetre mini jack | Yes, the standard form |
| 3.5 mm | Same connector with a space | Yes |
| 3 5mm | Same connector, punctuation lost | Yes, common in search results |
| 3,5mm | Same connector, decimal comma convention | Yes in many European listings |
| 35mm | 35 millimetre, unrelated to audio | No, this is film or a large diameter |
| 1/8 inch | The imperial equivalent of 3.5 mm | Yes |
| 6.35mm or 1/4 inch | The larger studio jack | A different connector |
Why the Notation Varies
Search normalisation
Marketplaces strip punctuation, so queries written with a space become their own index entry.
Regional decimal marks
Some countries write decimals with a comma, which becomes a space or disappears entirely in indexed text.
Unit mixing
Imperial and metric sizes coexist, and 1/8 inch equals 3.5 mm, which adds further variation.
How to Order Correctly
- Confirm the millimetre size, not the listing text.
- Count the bands on the plug to determine TRS or TRRS.
- Check the gender combination, plug to socket.
- Decide the length you need and add one metre.
- Check the plug barrel width if a case or recessed socket is involved.
Real-World Applications
- Replacing a lost extension without ordering the wrong size.
- Standardising a purchase list across a team.
- Buying from marketplaces where listing text is inconsistent.
- Distinguishing audio jacks from unrelated 35 mm products.
Related Guides
For the connector itself, read 3.5 mm extension cable. For the headphone case, see headphones extension cord. For larger studio plugs, start with audio jack extension cable.
FAQ
Is 3 5mm the same as 3.5mm?
Yes. The space is a search artefact rather than a different specification.
Is 35mm an audio connector?
No. It refers to a 35 millimetre film gauge, though listings sometimes use it incorrectly.
What is 1/8 inch in millimetres?
3.5 mm, the same connector with an imperial name.
How do I avoid ordering the wrong size?
Measure or compare against a known plug and confirm the pole count before buying.