The ground control 2bliss ready is an exceptionally versatile trail tire cad engineered knob shapes strengthen knob structure for optimum braking and traction but keeps knob surfaces adaptable for best ground control gripton compound helps make this the perfect choice for epic trail rides in any condition gt casing 60 tpigt bead foldablegt butyl wrapped bead 2bliss readygt compound griptongt 650b x 21quot psi 25 50 approximate weight 635g