The 3/8" socket wrench insert with a key size of 21 mm is a high-quality tool made from CrV steel. This material is characterized by its high strength and durability, making it suitable for various applications. The socket insert is designed for connection to 3/8" tool holders and is ideal for repair and maintenance work. Weighing only a few grams, it is easy to handle and can be conveniently stored in any toolbox. The silver tone of the metal gives the insert a professional appearance and facilitates identification in the tool inventory. Made in Taiwan, this socket insert meets high quality standards and is an essential aid for both professionals and DIY enthusiasts. Whether for use in the automotive industry, mechanical engineering, or general repair work, this socket insert offers the reliability and performance required for precise tasks.