This product is great, I bought the product a month ago when I got my first road bike. The idea behind buying this was so that I could put my phone on my bars as a health tracker or GPS if I was going new places.
After a couple of rides while using this I realized it was holding my phone very securely and therefore I decided to test it further with another phone and another bike. I put the phone on the bars of a BMX bike and went round a track completing a variety of jumps and stunts, even under so much stress my phone was held securely in place which leads me to believe that your phone should be safe no matter what situation you get yourself into.
The product itself came in a little envelope, it was packed with instructions on how to use and mount, although the instructions are clear enough, you may have to be a little forceful when stretching it around your phone as it's quite a tight fit, however you shouldn't worry as it holds the phone securely and seems to be strong.
I wouldn't recommend this to people with larger phones such as the Samsung Note range, I found it to be a tight fit on my iPhone 5 and Samsung Galaxy S4