The product has very good quality and I'm in the 32nd week of pregnancy and Size M fits perfectly. I usually wear clothes size 38 and now in the 8th month my belly has grown quite substantially. I think I'll get along with size M until the birth, because I still have a little leeway. I also had Gr. S ordered because I was not sure what would fit, I would personally Gr. S for pregnancy months 4 - 6 recommended. The strap is easily adjustable with Velcro and are stable, whereas the fabric over the belly is light and comfortable to wear.