I tried these panties on my Souldoll Zenith girl doll, they have similar waist and hip proportions to the SD16, so they fit perfectly! Considering that many doll outfit companies don't put underwear on them, this is one of the best options on the market ^_^

A very important item in the wardrobe of any self-respecting doll lady ;-)

In the second photo, a comparison with black color. The white ones were on the doll, they didn't lose their shape.