A fitting is any machine component, piping or tubing part that can attach or connect two or more larger parts. Examples are couplings, compression fittings, and piping and plumbing fittings. A tube tubular section, tubing, or hollow cylinder usually but not necessarily of circular crosssection, used mainly to convey substances which can flow liquids and gases fluids, slurries, powders and masses of small solids. Plastic tubing is widely used for its light weight, chemical resistant, noncorrosive properties, and ease of making connections. A tube may also reference a florescent light bulb or a housing of lamps or LEDs. Features. 0.25 Tube Fitting. Made with high quality materialSpecifications. Length 2.25 in / 5.72 cm. Width 2.6 in / 6.60 cm. Height 0.9 in / 2.29 cm. Size 0.25