My son is almost 2 years old so we are using this product to teach him when it is okay to get up in the morning and at nap time as he transitions from a crib to a toddler bed.  He is still learning how to use it but it is very simple to use (read all instructions first).  There are a lot of different buttons on the back but easy to figure out and hard for kids to access the buttons.  We put it on our son's dresser so he can clearly see if it is red or green. [This review was collected as part of a promotion.]