These are Mini E-Z Connectors for Park Flyers by Dubro.

FEATURES: Aluminum Construction

INCLUDES: Two Connectors
Two Screws
Two Washers

REQUIRES: Nothing

SPECS: Length: 4.8mm (3/16")
Diameter: 3.2mm (1/8")
Weight: 0.25g (0.0088oz)

COMMENTS: Maximum pushrod diameter is .047 - 3/64" (1.22mm)