Good, but does not qualify for 5 star.
This is my first eye retainer, so I do not know if there are more better products out there. I am sure there be with expensive price tag.
I liked it's grip but the material is uncomfortable behind the ear or with the skin. I wish it could be little bit smooth fabric.
I use it roughly 10 hours a day so good quality fabric is important.
I do not use it for sports purpose, so not sure how strong it will hold. But I believe it can survive simple running and exercise.
Oh yes, the vendor was very helpful in listening my concern.