Designed in Bozeman. Tested Everywhere. That is not just a clever marketing shtick. It's the truth. I am proud to say that you will not find another US based company selling barbless fly tying hooks that can say that they have actually taken the time to design their entire line from scratch. None.
The 523 is a 3XL version of the 516. To compensate for the additional leverage generated from the extended length I increased the wire diameter by one size, e.g. 523 #10 and 516 #8 have the same wire diameter.
This is a 3X long length hook with a 1X gape. It has a 60 degree down eye and is formed from a heavy weight wire. Available in sizes #4 to #14.