Improved casing and evo2 compound improve this light weight high performance tire made for hill climbing and tt outstanding light race day tire also zsg dual compound works in all conditions giving grip and feel no matter what the weather superfine ax casing is the perfect blend of suppleness and toughness to help ward off cuts and flats combines with the pt belt under the tread this is one tough light tire700 x 23c with black sidewall700 x 25c with black sidewallroad cc reviewthe 39l3