I recently bought the new Canyon Grizl in size medium, but I needed a longer stem (60 mm -> 70 mm). Canyon is terrible with parts, so they don't sell this D-shaped stem separately. Together with my bike mechanic, we looked for an alternative and eventually he came up with the FSA NS SMR-II STEM. This also has a D-shape and fit almost perfectly on the Canyon spacers.
Now, I know that a stem with round spacers would also work, but this post is more for people who want to keep the D-shaped look. Do with this information what you will. In any case, I am very happy with the result.
by NielsD91