I got this and the numbers set for our daughter for Christmas. She has opened these several times in the last few weeks. She is 4 years old and loves to practice writing her letters and numbers. She never gets bored of the repetition.
The front of these flash cards is the letter and a short sentence using the letter several times in tracing mode (allowing the child to trace the letter is upper and lower case). On the back of the cards is an activity associated with the letter and a section for the child to practice the upper and lower case of the letter several times.
I recommend this for those that like to practice their letters/numbers on their own. My daughter is pretty independent and only needs my help to know what activities she is supposed to do. Another great thing is it also helps her learn to draw. For example, she has to draw fish into the picture of the aquarium on the F letter card.