Kramer AD-BF/RM BNC (F) to RCA (M) Adapter

The Kramer AD-BF/RM is a passive in-line adapter that turns a female BNC connection into a male RCA. It is the piece that lets a BNC-terminated coax feed an RCA input on a monitor, recorder, or distribution amplifier without re-terminating the cable.

BNC is what the professional side of the composite and SDI world uses because it locks; RCA is what most consumer and prosumer inputs offer. This adapter sits at the point where those two conventions meet.