This product sucked because I definitely ordered it about 3-4 weeks prior to the mcat.

The person who made the previous post obviously didn't look very hard at the book or try to study with it, or they would have realized that the definitions upside-down beneath the words are NOT the definition to THAT word. This is a long, thin book of flashcards with a vocab word on the Front of the page and the definition on the Back of the same page. The book does go upside down, but this is because there are more words/defs printed upside-down, therefore using the entire page (since the single word/definitions only take up half a page). So the book read right-side up is Chem, and the book held upside down and read normally is half Chem and half Physics.
Personally, I love my MCAT Physical sciences flipbook. I take turns carrying the Physical science one or the Bio science one (also really awesome) with me at all times. Also, they have the recommended function of bending down/cutting off the corner of a page once you've mastered the word, and have gray corners for this purpose. This is really handy for flipping past words you already know.
I give it an A+. Don't listen to the other review, you DON'T turn it upside down to get the definition, only to start a new set of words. I highly recommend it to anyone who wants to study on the go.