The Rib Tank in Black from Knickerbocker, NYC. 

Details
The Rib Tank Is Crafted From A Custom-Developed Jersey Using Long-Staple, Dual Ring-Spun, And Combed Cotton Yarn. Its Drop Needle Construction Creates A Ribbed Texture, While The High-Quality Yarn Ensures Softness And Durability.

• 100% cotton, 6 oz. jersey.
• Made in Portugal.