This is a great product. It is well made and very fun. I would not recommend this for a 3-year old. Even my 4-year old is pushing his dexterity to the limits. But for a 5 or 6 year old, definitely.
My 4-year old grandson doesn't have the fine motor skills yet to put the little screwdriver bit into the screws slots. Maybe this is not the case for all 4 year old's and he only recently turned 4 year old. Once I did that, for him, he went to town on it and LOVED using the automatic screwdriver. That made his day.
I still give this an overall rating of 5 stars - cause just watching him play with his pack of dinosaurs made my day.