The Davis Mark 15 Master Sextant Micrometer Drum is a high-quality navigation tool used for accurately determining latitude and longitude. Made by the reputable maker Davis, this sextant features a micrometer drum for precise readings. It comes with a protective case for easy storage and transportation, making it a practical and reliable tool for mariners and navigators. Its classic design and practicality make it a sought-after piece for those interested in maritime navigation and antiques.