The NUNA PIPA Car Seat Series Insert can be used as necessary, to provide a snug fit for small babies. The low birth weight pillow can be used in the infant insert for even smaller babies, but should be removed once a snug fit can be achieved without it, at approximately 11 lbs. Fits all Nuna PIPA series car seats *Excludes PIPA lite RX & PIPA urbn Headrest patented Tailor tech ™M memory foam provides a comfortable custom fit GOTS certified organic cotton fabric & dye Grow-with-baby, two piece design Harness and crotch covers included Easy to Clean: Wash in cold water, delicate cycle. New in Bag~Never Used Fast shipping from a smoke free environment