This 23-tooth clutch gear is specifically designed for the Cosa2 clutch and fits with a 65T primary gear on the secondary shaft.
By installing the 23T gear on a Cosa2 clutch, the gear ratio is elevated to the level of a PX 200.
Please note that this 23T gear is not compatible with a 68T Cosa primary gear.
Check the RPM calculator to see how the top speed will change specifically.