HEIDENAU TIRE 400 - 18 K28 profile directional tread, square profile; perfectly suitable for old motorcycles and old vehicles. Please note, this tire can be mounted on 45cm diameter wheels, instead of 11x45 or 12x45 (Citroën, Renault, Peugeot from the 20s and 30s in particular). but: the current 12x45 tire is 14cm in flange width, and 73cm in outside diameter. the K28 tire offered as a replacement is 12.4cm in flange width and 69.7cm in maximum outer diameter. to consider before ordering!