This officially licensed Superman T-shirt features the classic Superman shield with a cool twist... It glows in the dark! Like a superman shield hit with a blast of kryptonite, this shield glows a super bright shade of green in the darkness and appears to be just a normal superman shirt in the light. Nobody will know about your T-shirts "Super Ability" to glow in the dark until the lights go out! This shirt is 100% soft cotton, machine washable and requires a minimum of 10 minutes of bright light exposure for maximum glow!