This is for a JC120, with a toggle switch for the power and a bright switch, often referred to as the "mid-period" version. How about using these as replacements to address scratchiness? Currently, some parts are impossible to obtain domestically depending on their specifications, making it very difficult to gather all the replacement parts for a single JC. These are not the inexpensive, no-brand Chinese-made parts sold on shopping sites. Chinese-made parts are significantly inferior in durability. These are made by reliable manufacturers such as ALPHA and TT Electronics. ・Some have short shafts, but knob installation is possible. ・The distortion potentiometer is a special part and is not included as it is impossible to obtain. ・There are two types of JC120 with bright switches; these are not compatible with the type that has a chorus adjustment hole on the back panel. ※Parts for JC50, JC60, JC77, etc. are also available; please inquire.