I got the WF-10-H line. The grain weight is stated as 305gr so that should give you some indication. The head length is 12.5m which is the same for 10, 11, & 12wt lines. There is a bar code label on the box... these are the associated numbers- 8 40309 12125 5
Hope this helps. I have not used the line yet but have it loaded on a reel for my upcoming Andros trip. Oh, oh I just saw the note saying the sink rate is 1.00 inch per second.