This star map keychain is made of high quality stainless steel and is 32mm in diameter. Engraved with the exact star sky as seen on the specific date, location, and time of your choice. You can choose from a variety of customization options, including adding custom text to the back of the keychain to make it even more sentimental. It makes a great gift for weddings, anniversaries, valentines day, birthdays, and more.