The Red DSMC Portrait Dovetails are part of an Arca-Swiss-type quick-release system for Red DSMC and Red DSMC2 cameras (Weapon, Epic , Scarlet-W, Scarlet, and Raven).
Red's DSMC cameras are unusual in the cine market for their ability to function in extremely compact configurations ideal for small-crew/no-crew cinematography and even for still photography. In those configurations, large heads using broad "Arri-standard" dovetails are less desirable than much more compact ball, pan/tilt, geared, gimbal, fluid, and other heads which use Arca-Swiss-type dovetails.
The Red DSMC Portrait Dovetails feature portrait-orientation dovetails aligned with the camera's optical axis. It mounts on the side of the Red DSMC Landscape Dovetails and is included with the Red DSMC L-Plate Package.
Unlike most Arca-Swiss-type quick-release plates, the DSMC L-Plate can rest on a flat surface because its safety stop pins are retractable (spring-loaded).
The plate's "capturing" threads are recessed from the mating surface to minimize cross-threading.
Note: officially confirmed by Red not to interfere with the camera's warranty