Features: Graduation: Inch: .001" Metric: 0.02mm or 0.05mm. Various models available with an assortment of dual scales. Measuring surfaces allow for the measurement of external diameters, internal diameters, depths and steps. Standard Acessories: The upper and lower scales on the slider are angled to reduce parallax error. Stainless steel with surface hardened measuring faces. Models are available with the slider operation in either plain, thumb clamp, fine adjustment.