Easy to assemble push-lock style fitting for rubber fuel, transmission, and PCV hose. Straight fitting in AN thread Lightweight black anodized aluminum Internal O-rings in the socket end Optimized socket entry, to allow for easier installation on the hose Push Lock : Reusable Push Lock : Tapered nipple for ease of installationPush-lock fittings are for use with soft rubber hose. Hose and fittings are easy to install: they simply push on with some heat and lubricant, and "lock" in place. The hose will not slide off the fitting because it compresses on the fitting as pressure increases.These fittings are made out of high quality material, precision machined, and anodized PROPERLY. This means you don't have to worry about them breaking, leaking, or fading over the years. Fittings are black anodized aluminum or red/blue. hose is rated for up to 300 degrees F and 250 PSI when used with rubber hose. Hose clamps are required to ensure the hose does not back off at higher pressures. Fittings can be used for all types of fuel, oil, coolant, hydraulic fluid, and pressurized air.