Quick answer: This is a Mares Liquidskin replacement strap for the X-Vision or X-VU mask.
Why it matters
Don't let a broken strap end your dive. Keep a spare in your save-a-dive kit.
What you get
Options
Before you buy
Choose the version for your mask. It fits the Mares X-Vision, such as the Mares X-Vision Mask, or the X-VU.