This is a Heavy Duty 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) and permanent or snap on mounting push nuts both included
Requires: Assembly onto linkages
Length of aluminum: 5.6mm (.223)
Diameter of aluminum connector: 5.5mm (.217)