Separate thumbwheels for bridge posts. Metric to fit Faber® 4mm bridge posts (BSWKIT, iNsert, E-Sert) or any 4mm posts using 4M X .7 thread. Imperial to fit Faber® 6-32 bridge posts, or any guitar using 6-32 size bridge posts (vintage Gibson, Custom Shop Gibson, and some years of Gibson Les Paul Classic Series)