Pickup problem

is the Seymour Duncan SH-4 JB Humbucker Pickup the same thing as the Seymour Duncan JB Jr Pickup?

cuz i want to buy a mustang and change the pickup but idk if its the same thing, and i dont want to alter the mustang desing. thanx

The SH-4 JB is the fullsized humber, the JB Jr is the singlecoiled sized humbucker.

Doog said: The SH-4 JB is the fullsized humber, the JB Jr is the singlecoiled sized humbucker.

but ahh how can i say this

do they um give the same effect

Yes. From what I hear you'd be hard pushed to tell them apart at all soundwise.