Up for sale is a 520-pitch steel front sprocket in 17t to suit the Aprilia RS125 two-stroke from 1996 through to 2010 (see listings below for more accurate fitment). This front sprocket would be excellent as a spare or replacement for your bike, or to change your gearing.
This will fit the following models of Aprilia:
RS125 2st 96-08 (standard size is 16t)
RS125 2st 09-10 (standard size is 17t)
36 Months (3 years)