Brass compression tube fittings include preassembled bodies, nuts, and sleeves for quick installations. The sleeve grips the tubing and as the nut tightens it compresses the sleeve for a tight seal. Metal fittings tighten with basic tools and can be used with multiple tubing materials in low-pressure fluid applications. Brass, an alloy of copper and zinc, is strong and resists corrosion from water, heat, acids, minerals, and peaty soils. Air, liquid, and chemical fittings are appropriate for a variety of applications. Engine and vehicle fittings are suitable for use with air brakes, coolant lines, oil lines, and fuel lines. Instrumentation fittings are made to tighter tolerances for high-precision instrumentation applications. Water works fittings connect pipes in water supply systems.