Moving the index arm causes the image to split in half. When viewing two objects, such as the horizon and a celestial body, the index arm is adjusted until the two are superimposed. The micrometer drum reads out the angle between the two objects. The micrometer rack is cut directly onto the limb of the sextant. The sextant's handle is made of hardwood with a brass plaque.
Custom engraving on the brass plaque is available.
Box A beautiful large handcrafted hardwood storage and display case is included with the purchase of the sextant. The case has two brass latches and a handle, and is lined with green felt. The sextant is fully functional, but has not been calibrated and is not intended for navigation. A nearly identical vernier readout version of this sextant is available. The only difference between these sextants is the micrometer drum vs. vernier readouts on the index arm.