When I bought them it was because I could not make up my mind between my 55# Damon Howatt x-300, my 60# Kodiak Magnum, 64# 1952 Grizzly, my 65# Martin Hunter, or my 70# Damon Howatt Hunter and they were spined 50-100#, so with 160gr Wensel Woodsmans I could use the same arrows no matter what bow I chose to carry. I wish I could afford some more, but out of the dozen I bought, I still have 9 of them and the ones I lost/broke are not the ones I have harvested 2 deer and 1 elk with! Those are still good (although covered in dried blood!)