This is an excellent tool for teaching your children letters and letter sounds. Not only does it play the ABC song, but each of the letters, when fitted into the slot, play a song related to what sound the letter makes.
Fitting the letters into the spot can prove to be a challenge for younger children, but at the same time, can help them with their fine motor control. I would suggest holding off on this toy until they are three years old. Otherwise, they get frustrated and scatter the letters everywhere - which is the one problem I have with this toy. The letters have an annoying tendency to get lost.
Overall, this is a nice fridge toy for kids to entertain themselves with while you're making dinner. And it has the bonus of teaching the alphabet and helping children get ready to read.