The Summer Chest is a limited edition Chance Chest that ran from June 19th to June 24th, 2014.
It is a 5x chest, and the new released Epic for the Chest is the Flameguard Platemail , which is a Mono Fire Epic Armor.
1 Chest: 40 Gems
11 Chests: 400 Gems
40 Chests: 1,200 Gems
11 Chests: 5 Fire Fusion Boost Armor