Review on MiSense Briefs Cotton Underwear Underpants Boys' Clothing for Underwear by Adam Rogers

I bought these for my skinny 6 year old son. He usually wears Asian size 120 or 5T pants. I bought size 6-7 (usually size 120/height 115-125cm) but I have size 130. They are a bit loose but not too big. Very soft and comfortable to wear and my son loves them. It says it's 100% cotton, but it's 95% cotton and 5% something (maybe spandex?). I wash in the washing machine but don't use a dryer. , so it is not compressed. (laundry icon indicates no dryer)