Phono plug   

Also known as RCA plug.  Used for audio, digital signals ( S/PDIF only) and video. Mono only.
Phono plugs are relatively inexpensive (unless gold plated)
and make a good contact.  They are not as sturdy as phone plugs or xlr plugs
for repeated use applications (patch bays, portable equipment).
They also are not recommended for situations where the signal (tip)
should never touch the ground (sleeve).