A turnbuckle is a mechanical device used to adjust the tension or length of cables, ropes, or rods. It consists of two threaded ends that can be rotated to either tighten or loosen the connection. Turnbuckles are commonly made of metal and are often used in construction, rigging, and various applications where secure tension is necessary. These devices come in different shapes and sizes, including open body and closed body designs. Turnbuckles are typically used in conjunction with eye bolts, hooks, or swage fittings to create a secure and adjustable connection. Their versatility makes them essential in many industries, including marine, automotive, and structural engineering.