Original CDV of Mosby, Fischer & Bro (Baltimore, Maryland) label and revenue stamp on the back. I'm not a CW expert, but. This is a previously unknown pose to me, personally. If you can find another example please let me know.
About 4" x 2.5", slightly trimmed, rounded. VG antique condition overall, with no heavy creases or albumen loss, some age-related staining and wear.