EK-HFB Fitting (High Flow Barb) is a soft-tube barb fitting, designed for use with flexible soft tubing such as PVC, EPDM, Norprene, silicone or any other type of compatible flexible tube. EK-HFB Fitting is a stylish looking variant of the classic high flow barb fitting and requires the use of hose clamps or similiar substitute for safest operation. The barb is made from nickel-plated CNC machined brass with quality O-rings while the ring is made from CNC machined aluminium. These fittings are fully compatible with EK-AF series (45°/90°) angled adapters. These fittings can be either tightened by hand or by using Allen Key 8mm (not included, available for separate purchase). Technical data: thread: G1/4″ BSP; 4.5mm male thread lenght, supported tube: 10mm (ID; roughly equalls 3/8″ ID), outer diameter of the tube: unlimited, outer diameter of a fitting: 19.8mm, installed height: 19mm, compatible tubing: PVC, EPDM, Norprene, silicone, most types of flexible tube ROHS 2.0 Compliant!