BSD (Alex Donnachie) Donnastreet signature tire. Based on the same proven rubber as the popular Donnasqueak tire, but with an all-around smoother tread for more grip and sidewalls that sit further around the side of the tire wall for better grind performance. Smooth centerline for low rolling resistance. Extra grippy and super squeaky compound. Tear-resistant silkworm casing. Max 110 PSI.