See also the previous discussion of the Leica R to Leica M lens adapter as well as a mounting plate for the R-adapter M.
Just arrived is the new Leica R-adapter M.
At about $310, one might say that the Leica R-adapter M is expensive. But my experience with other brands of lens adapters make one thing stand out with the Leica offering: the quality is first-class, starting with the packaging and extending (most importantly) to the lens adapter itself (and the tripod mount). Very well done.
A tripod adapter is included along with the lens adapter itself. Even the right sized allen wrench tool for attaching the tripod adapter is included. There is also a small cloth bag for the adapter itself.
Since other adapters already are at around $270, the about $310 price is a bargain for the impressive build quality and exceptional fit and finish, and even more so when one considers the included and sturdy tripod adapter, which is essential for the larger and heavier lenses (the lever arm of even a moderate size R lens exerts a significant torque).
Additional notes and experience are found / will be found on the R-adapter M page in Guide to Leica. Test results will be reported under each lens for the four APO lenses noted in the previous discussion of the Leica R to Leica M lens adapter.