Two layers, featuring an inner layer of close fitting cotton lycra and an outer layer of cozy cotton velour. The outer layer is cut very roomy, combining a built in blanket outside with the swaddling baby body sock inside. Welcoming warmth for keeping babies cozy on cool frosty nights! In pink, blue or yellow. Outer layer is 80% cotton, 20% acrylic, inner layer is 95% cotton 5% lycra.