Concrete support rod, also known as rebar, is a steel bar or mesh of steel wires used in reinforced concrete and masonry structures to strengthen and hold the concrete in tension. It is most commonly used to reinforce concrete, but it can also be used to form the structure of pre-stressed concrete. Rebar is available in a variety of sizes and shapes and is often used in conjunction with other materials such as wire mesh or plastic mesh. Rebar is an essential component of any concrete structure, providing strength and stability to the structure.