If you already own an M1-L and would like to upgrade to M2, all you need is M2 upper rotator.
It is recommed to use with larger 65mm Arca-Swiss Quick Release Clamp (QRC-65). For M2 Upper Rotator with QRC 65 listing click here
The upper rotator uses compression locking system and incorporates special tab to mark end points of rotator usage.
This listing includes: M2 Upper Rotator.
Note: EZ-Leveler-II and advanced rotator RD3L not recommended for M2 when heavier lenses are used.
User Guides and Manuals
QRG - M2 Series Gimbal Head Pano Head w/ RD8-II or RD16-II .pdf