* A standard paperclip: Paperclips are typically around 33mm long, so 27.4mm is slightly smaller.
* The width of a dime: Dimes are roughly 17.91mm in diameter, making 27.4mm a bit more than 1.5 times the width of a dime.
* The thickness of a typical smartphone: Smartphones vary, but 27.4mm is about the thickness of a mid-range smartphone.
It's a small size, but it's bigger than a grain of rice (which is around 5mm).