The Trijicon RMR Type 2 RM07 with 6.5 MOA red dot is the large-reticle variant of the workhorse RMR. The bigger dot is preferred for competition, defensive carry, and any application where speed-of-acquisition matters more than fine precision. Black housing.
Specs:
6.5 vs 3.25 MOA: The 6.5 dot is twice the visible diameter of the 3.25 — faster pickup in low light, easier to find under stress, but covers more of a distant target. Most competitive shooters running RMR pick the 6.5; precision shooters pick the 3.25. There is no wrong answer; choose based on use case.