This has the months of the year in different colored chalkboard circles. They come in two sizes. The small size has a diameter of ~4.5 inches. The large size has a diameter of ~5.5 inches.
These can be used as part of a birthday board. Hang them on your board with some ribbon. Students can decorate their own wooden clothes pins to attach onto their birthday month. You can also write their names on cut-outs (cupcake, birthday cake, etc.) and staple around their birthday month. The ideas are endless!