The Four-inch Polished Solid Brass Sextant has a slow motion control to allow fine adjustment of the elevation angle. The sextant measures 4 5/8 inches (11.7 cm) tall, 4 1/2 inches (11.4 cm) wide, 2 1/2 inches (6.3 cm) deep and weighs 12.3 ounces (346 grams). A built-in magnifier can be swung into position to assist in reading the German Silver vernier scale, and there are six swing-arm filters. The sextant is engraved "Stanley London 1880". While these models are functional, they are not intended for navigation. They are perfect for the collector or the beginner interested in learning celestial navigation. A beautiful handcrafted hardwood storage and display box with brass plaque is included with the sextant.