I have had this product for 2 1/2 years.  Both my children love it so much that I just bought one for our niece and nephew.  They just celebrated their 1st birthday.  My thought was that they could use it inside at first without sand, maybe just a water table.  Then later this summer add sand, etc.  The size is great for the little ones.  My two and four year old have loved theirs. Your children can really grow with this product.