Choose the correct size Woolbabe Sleeping bag or sleepwear item for your baby now. Choosing to purchase a size that is too big for your baby puts them at risk of it not fitting safely. If you're worried that you'll only get a few months of use, keep in mind that Woolbabe sleeping bags are generously sized and are the longest baby sleeping bags on the market. We often get positive feedback from parents that their 2 year olds are still using their 3-24 month size Woolbabe sleeping bag comfortably and haven't yet outgrown it.