High quality high flow fitting with a stop plug from Enzotechnology. A fill port allows users to get the liquid in and out of their liquid cooling system. It also eliminates the need for a reservoir. Compatible with 3/8" ID tube. Very unique metallic black plating finish! True Hi-Flow Design. High Quality Brass Material. High durability Nickel-plating finish RoHS Compliant Compatible with 3/8" ID tube Tubing ID 3/8" Tubing OD   Thread Type G1/4" Finish: Matt Black