This Woolino 4 Season Merino Wool sleep sack will keep baby warm and cozy all year round. I was truly stunned at how my baby girl was warm with just this one piece of fabric - and not too hot in the Fall or the Spring. It is washable on delicate setting with gentle detergent. I have washed it a handful of times, and the fabric color is slightly starting to fade on the seams, but the sleep sack is as soft as the day I bought it. 2 way zipper is perfect for middle of the night diaper changes. Size 18-36 months.