Pikkuna elements are not double-sided — each has a front side (facing you during installation) and a back side (facing away).
When measuring your opening, make sure to do it from the same perspective you'll use for installation — the front side of the element should face you.
All drawings we send for your approval show the front side of the element facing you.
This is especially important for trapezoid-shaped elements, those with doors, or with different fastening types on each edge. Think of it like Tetris — the PVC screen fits only into the specific opening when oriented correctly.