This is the Tactic 24" Servo Extension with Futaba J Connectors.

Features

Installs between servo and receiver for long extension runs in large
aircraft

Includes

Tactic 24" (610mm) Servo Extension with Futaba J Male and Female
Connectors

Specifications

Length: 24" (610mm)
Wire Color Codes-
Black: negative
Red: positive
White: signal (polarity tab is on the signal side)