I bought the 44lb set due to the types of weights included and the adjustable way you can move things around. I am not a fitness freak and just trying to get in shape more. This system is made of plastic, but it is a high quality plastic. It feels sturdy and solid!Everything is included in the pictures as is, but I wish they had included a second kettle base rod. The second handle for the kettle base is pretty much on its own since it doesn't have a place to go (unless you use it on a dumbbell or as a handle for pushups). Having a way to use two kettle bases at once would have been nice, or at least a way to store the last bit of weights so they are not loose.The yellow nuts are solid plastic and very sturdy. They screw on with no trouble and the threads on the entire system is of excellent quality. The weights on the dumbbells have not moved a cm since I got this a week ago. You will have an extra nut laying around due to the lack of a second kettle base. You could double up on one end of the dumbbells, or it will be used if you use less than 4 weights on the kettle base (needed to support the bottom).The barbell foam connector is nice and thick too. It is shaped in a rounded triangular pattern which allows for more stability. The only other thing I would improve upon is to provide both metric and imperial/standard systems on the weights. We can do the conversion easily online, but those of us here in the US cannot really fathom the difference between a kg compared to a lb. Although, I guess this will help us learn how to convert from kilograms to pounds.Overall, the entire system here is highly recommended and a quality set for the price. The plastic is really sturdy and feels like it will last a long time. I can only guess on whether there is a steel rod inside each bar (and if it is as thick as they say). But, the bars do feel that sturdy. Grab this system if you need a dumbbell set at home.