Adidas workout crop tank top size medium/large

Like new condition Adidas workout crop tank top. Only worn twice. Tag removed but is a size medium. Could also fit a large. I’m selling it because it didn’t quite fit me, there was some gapping at the back - hence why I think it could also fit a large depending on body shape and desired fit. Note: no padding or chest support in this top, to be worn over a sports bra.