I wanted to keep several small items in the banknote tray, so I purchased the one with the higher height, but it was too shallow to store and could not be stored much. The groove was digged one step deeply in the small incremental part of the small change tray, and when storing more than 10 sheets of curing, it became easier to count the number and the beginning was moved. However, there was a case that the 9th piece was caught in the groove, causing a result calculation error. I will make a chamfer on the lower vertical wall of the groove and I will try to modify the process later so that it will not become caught. When you close the lid, the stuck is strong and hard. I think that I wanted you to design with consideration a little more, such as chamfering angle of HOOK.