Gold Moons and Stars on Orange Cat Collar Accessory:Blank Moon Charm They are the same size

They are the same size (7/8")

Once charged the glow is best observed in a space that is completely dark

This customizable pet tag is a hand stamped metal 7/8" disk (about the size of a quarter)

The areas in grey will reflect light shined onto it

If you select "none" the collar will still include the ring

Gold Moons and Stars on Orange Cat Collar Accessory:Blank Moon Charm They are the same sizeThis design features glow in the dark stars. A note about any of our glow in the dark products: This item features glow in the dark pigments. It does not contain any electronic elements or batteries. The pigments require exposure to a light source in order to activate. Either indoor lighting or sunlight are effective at activating these pigments. If you live in a home that is often dark and doesn't have any sunny windows the collar may not receive