An adjustable wrench is a versatile tool that is used in many repair and maintenance tasks. It is also known as a crescent wrench, which comes from the company that first manufactured it. Other names for this useful tool include an open-end wrench, an adjustable spanner, and a shifting spanner. In some regions, it may be referred to as a monkey wrench, although this term is less common now. Regardless of its name, an adjustable wrench is an essential item in any toolkit, and it can come in a range of sizes to suit different needs and uses.