Borderlands 2 - The Highlands - Arms Dealing and Farming Eridium/Henry

In the Highlands, Zed will give you a mission to pick up some arms from mailboxes. The timing is tight, so I used a couple of shortcuts to make it quicker. Extra bonus at the end, farming Henry (2:45). He won't appear until you get "Best Mother's Day Ever" from the Fridge, when you're killing Shorty the Midget. He drops a few heads (apparently, seemingly very rarely) but also a LOT of Eridium. Enjoy