"A special prize box that contains one of hundreds of unique items that cannot be found anywhere else. It can only be opened with a Silver Key. Silver Keys can be purchased from Boost, the Special Items merchant."

This is from the lockbox on the usable section. It does not tell you where to get the actual box. http://wiki.spiralknights.com/Iron_Lockbox#Iron_Lockbox

Also it is lacking the chroma and graphics.

Also, the more heat you gathered the more it spins. I don't know what that has to do with the prize, but if anyone does know that can be added too.

This page has only just been made recently, but as i can't edit it (steam user) I'm posting this in hopes that someone might add the relative information.

also, WHAT DOES THE CHROMA DO!?