Thymus Lapel Pin Not Immune To Your Charm I Heart Guts Tantalizing thymus gland pin will give you a much-needed immune system boost. Celebrate the peter pan gland that stays small and never grows up! Learn thymus facts on the back of our cardboard display. Cute 1.25 printed aluminum pin made in China. I Heart Guts puts a smile on your face and smarts in your brain.