EK-HDC Fitting is a more secure variant of the EK-HD Adapter fitting as it prevents solid tube to be pulled out of the fitting by compressing the rubber gasket underneath the ring. The barb is made of nickel-plated CNC machined brass while the ring is made of black-chrome plated CNC machined brass and feature quality O-rings. These fittings are fully compatible with EK-AF series (45°/90°) angled adapters. Best practice is to install these fittings using Allen Key 9mm (not included, available for separate purchase). Model: 3830046992574.