A reminder, the history of climbing tools, and the pioneers who first figured out how to climb more difficult and wild climbs with them, are available on Amazon and Blurb. Makes for a great climber’s gift for the holidays!
Links for Mechanical Advantage: Tools for the Wild Vertical
AMAZON.com
Volume 1 (mostly European developments) : https://www.amazon.com/dp/B0CGZ2S58J
Volume 2 (mostly USA and global tools): https://www.amazon.com/dp/B0CH26LTFM/
BLURB.com
Mechanical Advantage, Volume 1 ($25) Best color version: Volume 1: $42
Mechanical Advantage. Volume 2 ($30) Best color version: Volume 2: $58