Vittoria Open Corsa EVO CX 700x 23c Blue / Black Aramid Bead. Vittoria Open Corsa EVO CX 700x 23c Blue / Black Aramid Bead. Corespun K 320 tpi casing with a blend of polycotton and Kevlar threads. Kevlar 3-D compound with added silica tread. PRB (Puncture Resistant Belting). Specificaly designed for Road Racing & Time Trials.