Sokka’s Rejected Weapons
九环双刀 - nine ring double sword; or ‘four’ in this case.
I’ve never seen them with four rings, and four (a homophone for death) is a rather unlucky number. Nine, on the other hand, is incredibly lucky.
Here, Sokka, let Old Dude show you how it’s done :P Do watch this! It’s cool, I swear!