See photos. It is $5 for both of them. These allow you to put a coax wire into a female RCA socket required by receivers, TV's etc.
• Nickel plated body for enhanced corrosion resistance
• Converts any RCA/Phono socket to a standard F socket, or an F plug to a RCA/Phono plug connector
• Can be used to help build and easy-on/easy-off cable TV connection
• Material: Zinc Alloy