This is the second set of these wooden cogs I've purchased. I got a set of these 4 years years ago for my older granddaughter who has had hours of playing with them and still plays with them now. So I've just bought a second set for my youngest granddaughter who is 16 months old and enjoys playing with the older granddaughters cogs. They are a robust quality toy backed up by the fact that the first set are still going strong after 4 years of regular use. They are educational as they have to be arranged in sequence to engage all the gears and they are just good fun.