Not mudbuckers.
The specs for this one says the neck and middle pickups are SG Rhythm Bass and the bridge is SG Lead Bass. But "the modifications consist of two bonus SG Rhythm Bass pickups." No, a regular SG Bass already has one SG Rhythm Bass pickup at the neck. Trust Gibson to get its own specs wrong.
IIRC up until a few years ago, these were called TB-Plus anyway. Same construction as in a Thunderbird (blades w/ceramic magnets beneath) but the coils were spread much further apart. I don't think that has changed, but I could be wrong.