The Moore & Wright 890 Series Fixed Type Depth Micrometer has a fixed depth rod with a 6.5mm diameter. It is fitted with a 'speeder' type ratchet and a lock screw for added user convenience. These fixed type depth micrometers conform to BS6468:1984. Base Length: 63.5mm / 2.1/2in. The Moore & Wright 890M Fix Type Depth Micrometer has the following specification: Range: 0-25mm. Resolution: 0.01mm.