Kramer AD-BM/RF BNC (M) to RCA (F) Adapter

The Kramer AD-BM/RF is a passive in-line adapter with a male BNC on one side and a female RCA on the other, letting an RCA-terminated cable plug into a BNC input.

It is the reverse of the AD-BF/RM and the one you want when the source cable ends in RCA and the destination equipment, typically a rack-mounted monitor, switcher, or DA, presents a BNC jack.