From threeA Wiki
Wave Two, oft stylized "WAVE TWO," is the second series released in the World War Robot Portable toy line by ThreeA. Wave Two was released for pre-order on 20 November 2009 and consisted of Bertie Mk 2 packs that included matching colourway Square²s.
The only Bertie Mk 2s that didn't come with matching Square²s were Desert Combat Bertie Mk 2, which came with Euro Defense Square², and Deep Powder Bertie Mk 2, which came with Winter Defense Square².
Wave Two packs
A list of packs released in Wave Two: