Review (5/5): Good quality, great for shorter hair
This sleep cap is really nicely made. The color is well named, as the item I received is a deep jewel tone, like in a peacock's feather. It's a much nicer color than on my monitor (the pictured item looks to me like "royal" blue).
The ties in the back allow you to adjust the fit; I haven't had them come untied. It's comfortable and nice not to have elastic digging into my forehead. There's not as much hair-space as in other caps I've used. This one is more for thin hair or a shorter hairstyle.
My short curls tend to flatten if I sleep mostly on one side, but if you aren't sleeping in rollers (or with your head magically levitated) that can't be helped. A light spritz of water in the morning takes care of the curls.
I expect this silk sleep cap to last a long while.