Radium 3/8 Inch Sae Male To 3/8 Inch Barb Black Nylon

Radium Engineering  3/8 Inch Sae Male To 3/8 Inch Barb Black Nylon plastic adapter fitting. 3/8 SAE MALE to 3/8 Hose Barb.

These adapter fittings are available in a variety of configurations. They push-on and secure to most modern USA, European, Japanese, etc. fuel injection systems and are used to convert an OEM SAE Quick Connect connection

To determine the required size, simply measure the outside diameter of the male fitting as shown below.
0.3125 = 5/16"
0.375 = 3/8"
0.50 = 1/2"