Sought these for some time before it occurred to me to check Wayfair.  Lo and behold, they offered several different versions of this shower curtain ring.

Surprisingly, pleasingly heavy for the price.  Cannot imagine better quality.  The polished chrome is "spot on" in terms of cool silver metalllic tone.

Client was frustrated by other shower curtain rings which would come loose.  That's when I decided to seek this style.  Very secure and easy to operate when it's time to change the liner or launder the fabric curtain.  

Thank you, Wayfair.  

Pros: Great value, better-than-expected quality.
Cons: None!