Each '2-Step' will now come standard with our regular BULLETPROOF 'heavy wetter' Insert of matching size. If our Stay Dry BULLETPROOFInserts are desired instead, be sure to add them by going to the Insert Upgrade page and place in your cart. Number of upgrades should not be greater than diapers ordered. Additional inserts may be ordered at regular price, but are found on the Insert Collection page. Remember: No Insert Upgrades for AIOs! A Liner comes with S, M, and L AIOs (not NBs).