I'm not even sure where to start with these rotating planispheres. They can be used to identify stars (above the horizon) in the sky in the from Earth's Northern hemisphere based on the month and time of day. It's a perfect gift for astronomy lovers and looks great just sitting on a desk or as a super intricate enamel pin, sure, but make sure it inspires you to find some constellations in our beautiful night sky! : ) Pin Grades Explained: -Grade A planispheres are our standard awesome planispheres. -Grade B planispheres have small cosmetic defects like: scratches, dents, or small discolorations. Grade B pins do not have functional defects, just cosmetic. Please note! This planisphere is for latitudes 30-60 deg in the Northern Hemisphere. I am currently working on a Southern Hemisphere version. If you'd like to be added to the waiting list, send me a message! As with any planisphere, this is some distortion/skewing of the star placements. The sky is huge! And comparatively, this planisphere is very small. As you can imagine, a lot of squishing in of information is required. While it's designed to be as accurate as possible, please keep the size in mind. If you need a less distorted version, and don't need something as portable, make sure to look for a much bigger paper planisphere that has all the info you want : ) If you have any questions, just ask! I'm happy to help you. ☆ Includes 1 planisphere packaged in a holographic pouch ☆ 3 pin posts with rubber clutches on the back (this is a very large pin --90mm diameter) ☆ Electroplated with an extra metal coating for increased durability ☆ Illustrated/designed in-studio @ The Sciencey ☆ All planisphere and pin designs are © The Sciencey. Your planisphere comes with handy basic operating instructions. If you'd like some additional awesome information about planispheres in general, this website is very useful: lovethenightsky.com/how-to-use-a-planisphere/ Your planisphere comes with handy basic operating instructions. If you'd like some additional awesome information about planispheres in general, this website is very useful: lovethenightsky.com/how-to-use-a-planisphere/