Hello! That is a tank for the Swedish market. They were put in Primaveras due to weight laws. light weight motorcycle, not ccm or hp, were of interest just weight. The law was later changed but the tank was put into all PV in Sweden until produktion stopped. The V50 had the "big" tank an was never sold with the small one in Sweden. There is probably a lot of these tanks laying about in Sweden, many have changed them for a bigger one. Have a nice weekend! Patrik