Reiner Gamma Formation.

C9.25, 2.5x TV Powermate, Red filter and DMK21AF04AS. best 300 frames from 1200.

Here's some info from The Moon Wikispaces.

Below is a Lunar Orbiter Mosaic from Map-a-Planet Explorer

A magnetic map of Reiner Gamma obtained by NASA's Lunar Prospector spacecraft in the 1990s