SwaddleDesigns zzZipMe Sack is perfect when baby is ready to graduate from swaddling. Made from plush fuzzy fabric inside and out with soft satin trimmed edges. The zzZipMe Sack (wearable blanket) also features a clever 2 way zippper: opens from the bottom as well as the top. The zipper zips down from the top making it easy to place baby into sack and also zips up from the bottom keeping baby snugly warm during diaper changes. So easy. SwaddleDesigns zzZipMe Sack has passed rigorous third party testing in the US and UK and meet CPSIA requirements. zzZipMe Sack has a TOG rating of 2.2 which is perfect for year round use and the TOG rating recommended for temperatures of 65 70 degrees F (the temperature range medical experts recommend for sleep environments). SwaddleDesigns zzZipMe Sack with exclusive zipper is a patent pending design. 100% polyester, machine washable and proudly made in the USA.