Weighing in at only 185 grams per shoe it will likely be the most highly technical and lightest shoe in your race arsenal. Minimally constructed for barefoot comfort, the Tri Fly Octane II from Pearl Izumi features a 0.9 mm Second Skin Upper which adapts comfortably to your unique foot shape to eliminate hot spots and offers superior breathability. The Tri Fly Octane II is constructed with Pearl Izumi's OCTANE 1:1 Power Plate, an octane grade unidirectional carbon for feather-light stiffness and anatomic support with concave shaping for an ultra low (6.5 mm) stack height. Direct-vent technology provides cooling and drainage while the Octane SL Insole provides unheard of support in a lightweight package. The Anatomic TRI Closure is specifically designed to eliminate hot spots and remove pressure from your forefoot so you can focus on the path ahead rather than your feet below.