Type-B to Type-A adapter
A USB Type-B plug on one end and a USB Type-A socket on the other. This converts a port rather than carrying a signal any distance, so it is usually a stubby dongle rather than a cable.
USB Type-B — plug
The chunky near-square plug on the back of a printer.
How to recognise it
- Almost square, with the two top corners cut off at an angle.
- About 8 mm across - noticeably deeper than a Type-A.
- Usually white or light grey plastic inside.
- Maximum speed:
- 480 Mbps (Hi-Speed)
- Maximum power:
- 2.5 W standard
USB Type-A — socket
The flat rectangle everyone pictures when they hear “USB”.
How to recognise it
- Flat rectangle, roughly 12 mm wide and 4.5 mm tall.
- Only goes in one way up, though it famously takes three tries.
- A white or black plastic tongue inside the metal shell.
- Maximum speed:
- 480 Mbps (Hi-Speed)
- Maximum power:
- 2.5 W standard, more with proprietary charging