Note - this set has no images, just letters, so it can be used anytime of the year. If you would like a set with corresponding letter images, you can find that product via the link below:
A to Z Domino activity mats
Set of 26 activity mats designed for use with medium sized 1 3/8 inch x 2 1/4 inch (3.5 cm x 5.5 cm) wood dominos. Here is a link to the the set I bought and used to design this activity.
Great activity for developing fine motor skills as well as building concentration and patience!