Personalization is purchased PER PRODUCT except for the Signature Snare, which includes it. You also get both RK books signed for $10 if you purchase the "Buy Both Books" options. If you buy a drum head and book, that will cost $20. If you only purchase one personalization add-on but order two products, you must specify which product for Mike to sign to you. Fill out the box for personalization at checkout and Mike will sign the item to that person.