The build quality is very good, especially for the money it asks for. There is no trace of plastic. Metal rings, metal supports/rod/ends. I have opened it at about 2.40m with a main curtain of 3.5 meters and 70cm for 2 side curtains with heavy fabric, and the sag in the middle (which is perfectly logical) is minimal. Put selotape where the rods connect to open and close the curtain without it "sticking".

I recommend up to 2 meters of opening for the rod if you want it completely straight. For more than 2 meters, folding curtain rods are not recommended. I wanted something economical and that's why I bought it.