The price, delivery and quality of this item is OK, the only problem is the size.
The strap comes with an adjustable velcro strap which, even at its tightest, is far too loose for my arm.
(admittedly, I do have quite skinny arms for a man, but even so, it should still fit!).
My arms are 28cm circumference, I wouldn't recommend for anyone with arms under 30cm.