If you already own an M1-L and would like to upgrade to M2 all you need is M2 upper rotator with larger 65mm Arca-Swiss Quick Release Clamp (QRC-65).
The upper rotator uses compression locking system and incorporates special tab to mark end points of rotator usage.
The M2 is compatible with Advanced Rotators RD8-II (recommended) and also the RD-16, RD-16-II as well as RD3L.
This listing includes: M2 Upper Rotator.
Note: EZ-Leveler-II and advanced rotator RD3L not recommended for M2 when heavier lenses are used.