# Square openings help USB-A plugs stay securely connected in ports

- URL: https://talkfuse.com/story/why-do-some-usb-connectors-have-those-2-square-holes/
- Published: 2026-11-15T16:45:00+00:00
- Updated: 2026-11-15T17:13:22+00:00
- Original publisher: Engadget
- Original article: https://www.engadget.com/2313749/why-some-usb-connectors-have-2-square-holes/
- Topics: Gadgets

## Key points

- USB-A’s square holes help its plug stay in place.
- Clips inside the port lock into the holes.
- USB-C uses a different retention design.

## Summary

The two square holes on a USB-A plug are part of a retention mechanism that helps keep the connector securely in its port. Spring-loaded clips inside the port fit into the holes, reducing accidental disconnections during charging, file transfers or use of peripherals.

USB-A was designed in the late 1990s as a widely compatible connection for devices such as keyboards and printers, but it can only be inserted one way. USB-C uses tabs inside the port that latch onto notches in the plug, allowing its reversible design without square holes. Although USB-C is now common, USB-A remains widely used in offices and accessories.

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Summarised by TalkFuse (https://talkfuse.com/). Quote the original publisher for the reporting and link this page for the summary and discussion.