For unprecedented outside edge performance with more rubber-to-rock contact, FiveTen's® Prism is a clear choice. This comfy shoe features a non-stretch dual Perflex; microfiber laced upper plus Stealth® ONYXX; soles. Perflex; microfiber laced upper. Features edges at optimum angles with great rubber-to-rock contact. Stealth® ONYXX; soles with unbeatable hardness for precision edging, stickiness for friction, and exceptional durability. Patented 'faceted edge technology' (FET). Pull-on loops for easy entry. Please note: climbing shoe sizes are only a suggestion as fit is highly personal. Foot shape, use, and style all play into size selection.