Organic Essential Tank. The Essential Tank is a classic wardrobe staple in organic Pima cotton. Our Essential Tank is perfect for layering or wearing on its own, this 1x1 rib jersey tank is fitted but stretches and returns to shape. The Essential Tank has practical, bra-friendly straps and a sporty scoop front & back neckline. Length is approximately 26 inches (size small) from highest point on shoulder to center back hem.