I give 4 stars for the following reasons: 1) ambiguities in the diagram that take a lot of time to put a simple bin, 2) the supports are plastic, they bend somewhat when pressure is applied, and you realize that you need to be careful about how much weight you put inside, 3) the bin came out of its position twice, so opening and closing the cupboard needs to be done carefully, not abruptly.
The positives are: a) sufficient capacity if you don't have space to put another bin elsewhere, b) it goes inside the cupboard so the garbage is not visible from an aesthetic point of view, c) it is convenient when doing kitchen chores to be able to throw things directly, for example, leftovers, d) it fits in both right and left cupboards.
COMMENT: if the cupboard has a shelf in the middle, it is possible that the bin does not fit and the shelf needs to be removed.

You fold the diagram paper in half and follow only the instructions on the right or left side, depending on how the cupboard opens. In the placement of the bin, there is a missing precise measurement in centimeters for the distances between the three supports that hold the bin and lid.
Informally, the lid is stationary. Only the bin moves back and forth and goes under the lid.
To stand on its base, the bin has two supports. One support has a receptacle (a small round hole) where a pin under the bin goes. This support is placed in the stationary part of the cupboard, almost at the bottom and close to the door opening. The other support has a pin that moves in a path under the bin. This is placed on top of the cupboard's leaf that opens and closes. You have to find the correct distance by trial and error and you need a pencil to mark the upper limit and the position of the screws. For the third support, where the lid is connected, again you practically find it and mark the point with a pencil.
But since the bin has a specific size, they could have included measurements in centimeters/millimeters.
Inside the package, there are: the external gray bin, the gray lid, an internal black bin with a handle (where you put the bag), three plastic supports, 6 screws, and a plastic peg that holds the bin and lid together.