Mamia White Apparel Girl's Seamless Crop Top Undershirt Bra (Pack of 6) Girl's seamless crop top undershirt bra. Nylon material offers very stretchy and comfortable feel. Choose from various designs and cute prints. All packs contain a total of 6 pcs and feature assorted colors. 90% Nylon, 10% Spandex. Size guide (Small: 2 to 3 years, Medium: 4 to 6 years, Large: 6 to 8 years old). Please keep in mind this is a standard size guide, and the individual's weight should be factored in when choosing the correct size.