I have owned legos since I was a child and now purchase them for my almost 5 year old son. The cement mixer is part of the lego city collection. This is recommended for ages 5+. My son has been playing with these size since his 2nd birthday, but alot since his 3rd birthday. This is a new piece this year.
This has 213 pieces and he couldn't build it all by himself but there are several parts that he can get built. It was broken down into 2 different bags and then also has step by step instructions making it easier to build as the box shows. I like that instructions are included.
The legos themselves are constructed out of heavy duty plastic and are quite durable and strong. They can be stepped and will not break (but do hurt!). I find it pretty impossible to break a lego pieces. Legos are now built with more specifically molded parts so it is not as versatile as I wish, you could use some of the pieces if you wanted to build something different, but for the most part you could only change the layout of the truck slightly.
The play value with this is great as it is very detailed and even comes with cement to mix that actually will pour out of the back. The little guy can also hold the lever to pretend he is working. We have a large city and my son will sit and play with it alone or with the city for 30 minutes at a time often. He enjoys tearing it apart also and making his own creation, but being 4 1/2 to me it doesn't look like anything, he does not care though.
Legos are pricey, but built to last and are durable to passed down from generation to generation. We love this cement mixer and I would highly recommend it.