In-N-OutLarge and X-Large sizes for MilkshakesLarger SizeYou want your milkshake, now all you have to do is ask for it in a "large" or "extra-large" cupMost Locations3 - Medium-LowVaries by Sizehttp://hackthemenu.com/in-n-out/secret-menu/large-milkshakes/It's so simple, right? Upon request, you can order both In-N-Out Large Milk Shakes and In-N-Out Extra Large Milk Shakes off of In-N-Out secret menu . In-N-Out are famous for their delicious milkshakes, but they disappear so quickly. But if you know the secret to ordering a large or extra-large then the goodness can last much longer. There isn't mush else to say, other than that In-N-Out's milk shakes go great with their fries and burgers. So, treat yourself to a large or an extra large shake off of the In-N-Out secret menu. You can even try the secret Neapolitan Shake . Yum! Be sure to check out the In-N-Out Secret Menu as well as visiting our home page to check out the complete list of All the Secret Menus from all your favorite restaurants!