100% cotton. Adapt Women's tank tops are relaxed and less fitted than their women's tees.

Model is wearing a small. See size chart below (note measurements are general and may not be exact). 

S- Chest (29-31) Waist (27-29) / M- Chest (30-32) Waist (28-30) / L- Chest (34-36) Waist (30-32) / XL- Chest (38-40) Waist (32-33)