Lululemon‎ Open Back Tank Top S/M 4 or 6 Gray Swoop RARE READ

Lululemon Open Back Tank Top S/M 4 or 6 Gray Swoop RARE READ. I think it is a 4 or 6 - see pics for measurements. Please review all pics and details prior to purchase. Measurements are hard to take because the material is super stretchy, feels like a cotton or cotton blend. Measurements may be different depending on how much the top is stretched. Please keep that in mind when reviewing the pics. The measurements may vary depending on who/how they are taken.