1STANDARD SIZE: With stand 8mm rod diameter and precise 8mm hole, this centering holder is easy to connect with dial test indicators, allowing for seamless connection. 2HALF ROUND DESIGN: The half round dial indicator holder is perfect for special scenarios, enabling the user to locate the center of shafts or holes on machine tools. 3STEEL CONSTRUCTION: Made from premium steel, this curve dial indicator holder is sturdy and resistant to deformation, ensuring long lasting durability. 4RUST PREVENTION TREATMENT: The curved bracket undergoes black process, making it resistant to rust and increasing its lifespan, even in challenging environments. 5MULTI FUNCTIONAL: This holder serves as a versatile bracket for mounting test indicators equipped with valve stems or dovetail joints, providing flexibility for various measurement needs. 1 xHalf Round Dial Indicator Holder 1 x Storage Box