I believe these are what MasterPull use on their lines. Not all hooks are created equal by any means. How they "fail" is big difference, besides rating. In simple terms the hook you have will fail is a safe manner (opens up slowly) vs. breaking without any warning. In 14 years of instructing, I've yet to see a hook fail. **knocking on wood**I'm running, well ran, a Gunnebo style hook on my 3/8" synthetic line with the same style thimble. I had originally just used a shackle, but I decided to go with a hook after I had to winch about 1000ft up a muddy ravine. With that many resets a hook would have been really nice!!!