I am very surprised that something as stupid and fundamental break when first ... The plastic nozzle for screwing the weight broke (it is cracked between two points) and in that the weight on the side where the screw is broken, roam continuously in use and which makes it impossible to use.
I hope this is a simple manufacturing fault because I've ordered two and the second is still not happened.
Besides this defect, these dumbbells are all there is more classic and for its price, steel screws have been recommended, especially for weight 10Kg where their role is fundamental.