Cuban link bracelet... Literally anywhere you can buy almost anything.

Seems to be a 6mm width. Go on amazon or etsy and pick one up. They are fairly cheap.

Pay close attention to the clasp and how it attaches to the chain in this listing now look at this one.

Clasps aren't an direct indication of quality, but a split ring looks less handsome and it is usually less durable.

Just know what you want, and know what to keep an eye out for.