Personalized Christmas Letter M Santa Hat Alphabet Long Sleeve T-Shirt. Cute Christmas holiday Long Sleeve T-Shirt - Kelly Green with monogram M alphabet letter topped with a red Santa hat, great for a family photo. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL