The weight plates are quite large, especially the 2.5kg discs. When da 4 has on a weight, it is believed there are 20kg + on it, but this is only 10kg. So it's even less for dumbbells, what I've seen.
The diameter of the rods is perhaps a bit too small. Is not as optimal access to, it could have 5mm diameter longer.
The screws rotate very well. Once antauchen with your finger and the screw turns almost all the way up or down. So it will save you a lot of time when changing the weighter. They can be very tighten, the weight plates not wobble.
With these dumbbells can be trained very well. In terms of size it would go even smaller, in my gym the 10kg dumbbells are smaller by 2/3, which are made of hard rubber or something. Cast iron was still a possibility, even less.
Perhaps the relatively massive dumbbells interfere with some exercises, but until now I have not had the pleasure. I think at this price are the best, with 30kg weight. Some dealers you pay 30 for "a" dumbbell.