Amazing sleep lies ahead with the woolino sleep sack, a true lifesaver and much-loved brand for good reason. This mid-weight sleep sack made of merino wool and organic cotton has a two-way zipper that goes nearly all around the sack, plus seat belt openings on front and back for cozy car rides. High quality materials, easy to use, relied on by parents everywhere. No rips, tears or stains. Woolino sells a single size for 2 months to 2 years, with additional underarm snaps that secure smaller babies.