Are you a heavy sweater especially on the elliptical machine, for example? Your purchase of a Tee or Tank Top with Pocket and Mini-Towel already comes with a white, mid-weight mini-towel (9"x9"). If you would like a thicker, heavier, and extra absorbent mini-towel you can order it here (also 9"x9"). It is Oeko-Tex certified and 100% cotton. It is great for treadmill, elliptical and cycle but is not ideal for running because the extra weight of the mini-towel can feel a little bit too bouncy while running.