Personalized Mechanical Christmas Tree Women's V-Neck T-Shirt. A Christmas tree made of red and green mechanical gears is a humorous holiday design to tickle the funny bone of your favorite mechanic or mechanical engineer any time of the year. 5.0 oz., 100% pre-shrunk cotton Athletic Heather is 90/10 cotton/polyester 1x1 rib collar with mitered v-neck Shoulder-to-shoulder taping Ladies' fit