It seems your card is either a UX4 or UX5, the difference being that the UX4 has a small "USPOD" watermark in monogram; whereas the UX5 is unwatermarked. Given that the UX4 is a relatively rare piece, odds are you have the UX5.
If you're interested in the addressee shown on the card, I found a brief biography of the person:
Quote:
DELOS ROCKWELL, born Troy, Pa., Aug. 28, 1837; a lawyer. He was admitted to the bar of Bradford County, Pa., in February, 1862. He married at Troy, June 9, 1864. Eliza B. Smith, born at Elmira, N. Y., June 29, 1836. They settled at Troy, and were living there in 1895. No children. For many years he has been a prominent lawyer at that place. He was elected a Senator of the Legislature of the State of Pennsylvania in October, 1874 and was a valuable contributor to this Genealogy of the Rockwell families in 1891.
(I have no idea about the "C" stamp shown on the reverse, but probably a marking unique to the local post office.)