●Electric hammer bishan (16 teeth for hex shaft) ●Perfect for hitting stone surfaces and for concrete surfaces! ●Please be sure to install it on an electric hammer (hammer drill) and do not use it for other purposes ●Note: Fragments of fragments may hit the body. Please wear protective glasses, dust mask, and other protective gear such as work gloves or leather gloves ●Specifications: Size: Length 7.1 inches (18 cm)