Deletion of Fifi hook

Comment: With a simple  style search, I was easily able to add the Alpinist ref above and three book refs to the article. This is a standard piece of equipment used in aid climbing, different than a skyhook, and is described in multiple reliable sources sufficient to pass . The nominator really should take more care to perform a proper  search before wasting other editors' time
Stance: keep
Cited policy: Wikipedia:Articles for deletion (WP:BEFORE||WP:GNG||WP:BEFORE)