My son received this as a Christmas present. He's very happy with the product. I was happy with the price and the quick shipping. I would buy from this seller again. with the plastic container thing to hold them (no cover though)and usually some unique figures you can't get any other way. All the parts are interchangeable and you can create hundreds (maybe thousands) of fun and unique Ben 10 creatures. My son uses them as models and has a great time making comic books, writing stories, and just generally being creative with all the pieces. These sets also come with cards that my son loves to collect.
 
I don't recommend them for homes with younger children who still put things in their mouth or homes with pets who would eat them (yes my ex's dog tried to eat one of them!) or play with them (one of our cats loves to bat them around).