Personalized Big Brother Muscles T-Shirt. Big Brother! Protects his little siblings from all the bad stuff in the world. Great gift for your little hero! Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.