Chests are the primary source for special items that can spawn other items. They are also mergeable, and you can get better parts from your chests when you merge them to higher levels. When you gain a Chest, you need to place it on your board and click the Open button in the infobox. Chests have cooldown periods, and you need to wait after clicking the Open button. The waiting time depends on the chests' level. You can only open one chest at a time. Once you open the chest, you may tap and spawn the items whenever you want.