I just asked someone yesterday (when I had my 11 year old son with me) what it was for. He told me, and DS said "Mom, I want to get one. There's a girl in our school who has cancer. She won't be there tomorrow because she has to have that che something stuff, but I'd like her to know that I want her to get better".
Boy was that a great opportunity to tell my DS how proud I was of him, and talk a little about chemotherapy and exactly what it is and why his classmate won't be back for a while. I'm glad you posted a link, because I will be using it in just a minute.