Autobahns classic Dual Durometer featuring a 97a outer and a hard inner core. Featuring Ultra formula with FlatOut technology in standard shape and 97a hardness. This new version features a harder core for a firmer bearing seat, increasing stability at high speeds and powering through turns. Formulated to slide longer, roll faster, and never flat spot, the exclusive FlatOut compound allows complete confidence in any situation, at any speed. No flat spots, no uneven wear, no compromises.