The SM-13LH Vernier Micrometer is a left-handed version of the SM-13. Compared to a standard micrometer, the spindle on a left-handed micrometer travels in the oposite direction during operation. For example, the spindle on the SM-13LH will retract when the knob is rotated clockwise. The SM-13LH can be used on stages where the micrometer mounting is on the moving (top) platform of the stage (such as 460A or 460P series stages) so that turning the micrometer's knob moves the stage in the direction of the micrometer travel (just like a standard micrometer mounted to the fixed platform of a stage does). The SM-13LH has a 13 mm travel range and a 9 lb load capacity. SM Series micrometers have 0.5 mm pitch (50.8 TPI) threads and read directly in increments of 10 µm, with vernier reading of 1 µm.