in general , I love aden + anai . I have they burp cloth and swaddle blanket , and I have be very happy with both , so this sleep bag seem like a perfect purchase for the summer . however , after just two or three use and two wash , I find a giant hole in the bottom where the fabric have pull apart at the seam . the muslin itself pull apart -- not the seam -- so it be hard to fix with a sew machine . at the time I use this , my baby be almost seven month old but not yet roll around a lot when she be in the crib , so she do not subject the bag to any abnormal wear and tear . the four layer version might be sturdier , but also heavier for the summer . we live in a temperate climate without air conditioning , so have a light bag for the summer be important . unfortunately , though , the single layer of muslin do not stand up to any use .