It is an ideal correction tool for processing mold, hard alloy, glass apparatus, jade carving, etc ; Heads Shapes:Spherical, Ball; Head Diameter: 1mm; Grit:120; Shank Diameter: 3mm(1/8") Suitable for dremel, electric grinder, carving machine with a 1/8" collet ; Product Name: Spherical diamond grinding head, diamond ball, diamond carving bit