Your height: 5'1" to 5'6" (156 to 168cm) approximatly (?).
Frame size = 20in/51cm
Comments:
High quality and light weight, slick front tire, alloy wheels, Cro-Moly frame, a few scratches.
Mountain Bikes: they are sturdy and designed to go everywhere including off-road. Good for rough riding. In general heavy and with deep thread tires slow on paved roads. Not good city bikes unless narrower and slick tires are installed.
21 speed: perfect to go everywhere including going up very steep hills. There are 3 front chain rings and 7 rear gears. - Derailleur: Suntour