Grivel Star Crack Gloves have been made in partnership with Vibram, featuring their world-famous XS-grip rubber. Used in climbing shoes, Vibram XS-grip rubber ensures maximum friction and better coverage. The Velcro closure is covered with rubber to ensure greater strength and durability. The various sizes to choose from allow you to get a snug fit on the hand so you're ready to take on your next crack with no worries.