GihuoMen's Winter Fleece Pants Sherpa Lined Sweatpants Active Running Jogger Pants

What's the best way to wash these? Cold wash while having the pants inside out?

What size do I need? I wear 32w and 30 inseam.

What size should I get if I'm 38 by 28?

There are 3 versions of gihuo's pants ( asin : b08jfxgzhf; asin : b07zv7ksy1). what are the differences?