West Of Melrose Open Back Onesie. Crafted with soft and breathable fabric, this onesie features short cap sleeves and a flattering scoop neck, offering a stylish and comfortable fit. Features a built-in bralette. The standout feature of this onesie is its open back design. With its short length, this onesie is perfect for warm weather days or layering with your favorite jacket for a night out. Approx. inseam: 4.5''. Shell: 87% Nylon, 13% Spandex. Hand wash. Imported.