What a Clever Puzzle!
This is the chain store puzzle and the task is to store this chain inside of this box. Without any pieces producing over the upper Edge sounds easy, but you will immediately notice when you start that there are a lot of possibilities, how this can be arranged, and you literally will never fit inside of the Box, because something always does not really fit. First thing you need to understand is applying the right sequence of moves. Yes, the right sequence and orientation of the pieces, so you take the right piece. You flip it around here all the way and then flip it upwards.
You take the left piece and also flip. It all the way around, so you end up in this configuration. You need to flip this one upwards and then also this one upwards, because this configuration fits perfectly inside of the box without no pieces protruding over the other Edge