Very bad! A few modifications and Velcro and it works ...
No instructions in box. I figured out how to use the clasp by looking at the pictures here on Amazon. The clasp is cheaply made and I effective. I had surgery for a bicep tear and the clasp would slip or release and drop my arm. Very bad!  A few modifications and Velcro and it works great. Definitely more comfortable and a lot less hot than a traditional sling. This thing would be great if the manufacturer would just improve the clasping mechanism.
Rating: 3 stars