I never received the items. The package was delivered to a post office and not to the address of my freight forwarder. AliExpress says the package was collected by me but I actually live 2000 miles away.
Rings are really nice and solid as on discretion delivery was very fast ( come to UK in around 2 weeks). Only problem is that you must have special pressure machine to install rings on curtain as I didn't check correctly so it was my mistake and now I must spend another £50 for machine to do my curtains.