Do their job well, see the original a little cheaper than in the picture

Your job meet the parentheses really good. In particular, the slightly rubberized pressing surfaces are useful because they keep clothes well. Also directly on the rods of the clothes stand they adhere well, they do not slip axially. The spring force seems to be a good mix of handling and required strength.
The standard of construction appears in the pictures but a little better than in the original, showing the colored plastic inserts "solidification lines" - injection noses or sharp points but I have not yet found.