Check the Switch on your bike to be sure this is what you need before you buy. Measure the outer diameter of the threaded outlet on the gas tank, not the inner diameter of the petcock nut.
Fitment:
For 1980-2007 CR125R
For 1980-2007 CR250R
For 1981-1982 CR450R
For 1982-1983 CR480R
For 1984-2001 CR500R
Package Included: 1 x Fuel Valve Switch with O-Ring