Schwalbe road plus road tyre puncture protection level 5 at an affordable price puncture guard in road plus is ca 3 mm thick but not as highly elastic as smart or greenguard the classic center rib tread design provides acceptable rolling characteristics schwalbe road plus tyre specifications size etrto 28 622 28 x 110 700 x 28c inch etrto 32 622 28 x 125 700 x 32c inch etrto 37 622 28 x 140 700 x 35c inch etrto 40 622 28 x 150 700 x 38c inch compoundschwalbe basi