Value packs for filigree dread/braid cuffs come in packages of 50 and measure about 8 mm in diameter when they're completely closed. They're easily bendable, though, so you can squeeze them onto larger dreads if you leave a small gap in the back, or you can double up two at a time and make one really big cuff instead. These cuffs have ridges along the sides that make them look like corrugated tubing.
Size: 8mm x 16mm.
Brand: I Kick Shins.