L-shaped connectors, also known as elbow connectors, are fittings used to change the direction of flow in a piping system. They are typically made of polypropylene (PP), which is a thermoplastic polymer that is lightweight, durable, and resistant to corrosion and chemicals.

PP is commonly used in piping systems due to its low cost, ease of fabrication, and chemical resistance. The L-shape of these connectors allows for a smooth change in direction, reducing turbulence and friction in the flow of liquids or gases.