Personalized Keep Calm Jingle On Youth T-Shirt. Funny Christmas Youth T-Shirt - White with with jingle bells says KEEP CALM AND JINGLE ON. Perfect for sleigh rides and Christmas celebrations. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.