The DPN holders use thick, durable elastic and wide rubber caps so that any thickness of knitting needle or project fit into them. The elastic stretches to fit over your needles without putting pressure on them, protecting the tips from catching on whatever else you're carrying around.
Available in 3 sizes:
The red 5" DPN holder is made for the short sock needles
The blue 6" DPN holder is what most needles fit into. These hold sleeve or hat knitting needles
The yellow 7" DPN holders are the largest size
2 are shown in picture. The price is for 1 needle holder