This is an EZ Connector set by Dubro.
EZ Connectors link a pushrod to a servo arm allowing it to pivot for
less bind in control surfaces.

FEATURES: Works on 2-56 and smaller wire (.078")
Permanent or snap on mounting push nuts both included.

INCLUDES: Two brass EZ Connectors
Two plastic snap nuts.
Two metal snap nuts.
Two 2.5x3.5mm slotted head screws.

REQUIRES: Assembly onto linkages

SPECS: Length of brass connector: 10mm (.395")
Diameter of brass connector: 5.5mm (.217")