We Match! Big Guy & Little Guy Adult & Baby/Kids Two T-Shirts Set Choose both your t-shirt and T-Shirt size. Approximate sizing for the T-Shirts: 2T (Up to 7 pounds, Navy); 3T (7-17 pounds, Navy), 4T (17-25 pounds, Navy), 5/6T (25-30 pounds, Navy). T-shirts are standard adult unisex sizing. Both t-shirts are 100% cotton. This will make the cutest facebook/instagram/pinterest pictures! Excellent quality, comfortable and fun.