Use barbed fittings with soft tubing in low-pressure applications. They provide a quick and easy connection without the need for installation tools. Selecting a fitting is easy barbed fittings are sized to match the inside diameter (ID) of your tubing. To connect, simply slide the tubing over the barbed end of the fitting. In most cases, a clamp is required for securing the tubing to the fitting. Single-barbed fittings minimize leaks by having a smoother sealing surface than multi-barbed fittings.