This is a high frequency barrel connector used as an in-line splice connector. 

The internal components of this fitting are much different from a standard VHF/UHF barrel connector.

The center coax conductor indexes into a close tolerance tube that is resilient (spring) brass and is gold plated.

The close center-tube tolerance assures a tight connection, the gold plating assures a good electrical connection and the overall performance is greatly improved over standard designs. 

Internally, the center conductor tube is insulated from the inner skin of the barrel by a maximum air gap which results in much less RF loss. Insertion loss is extremely low and not really necessary to consider in complex systems.

DIRECTV approved.
Internal components are designed for high frequency.

• Gold plated center conductor assures minimum RF loss & good electrical connections.
• Resilient internal metals for dependable repeated insertion connections.
• Can easily be used in wall plates using the included washer and nut.
• Minimal insertion loss.
• Indoor use only.