Attracting visitors for over 145 years, thecrystal cave in Kutztown, PA is a mainstay foradventure. Inspired by the unique geology andnatural formations within the cave’s walls, thisProGrid Omni 9 offers a gemstone-like opulence.Iridescent in color, the shoe has been treatedwith an anodizing process that creates a “crystal”effect throughout the upper. An open mesh baseshifts between colors when the light changesfocus.