The Schiesser Boys Vest in size 152 fits my son (10) perfectly. The fabric (95% cotton, 5% spandex) is cool and feels good on the skin. If not for the would be a disturbing seam in the shoulder area. Unfortunately, it is precisely at the point where the strap of the backpack rests, it is therefore pressed into the skin and it feels uncomfortable. The other side is perfectly finished.
Washable is the shirt to 95 ° C, it is suitable for tumble drying and keeps the shape.
Conclusion: If the thickness seam would not, I would give it five stars, so there are three, because my son can wear it only for sleeping.