0/3M-6/9MGood news! Our beloved Ruffle Footie now comes with a zipper! All the same comfy ruffly goodness with the ease of a zipper for quick changes. Sizes Preemie through 6-9 months are our Classic Layette fit with a larger ruffle while sizes 9-12 and up are Fitted and feature Kickee's signature Muffin Ruffle. Not treated with flame retardant.