Treasure

Treasure Chests are droppable uncommon treasure items, In the same fashion as TF2's Mann Co supply crates. They can be opened with a Treasure Key, which can be purchased from the Store or obtained through a trade. Treasure Keys and Chests are tradable, though Treasure Keys require a waiting period after purchasing to be traded. When a chest opens, a five second timer ticks down and player receives a random item from within. All unboxed cosmetic items will be Strange quality, Also like TF2 crates.

Series #9
Given out during the Steam Summer Sale 2012, available till July 31, 2012

Series #10
Given to early buyers of The Defense 2 Pass