-Our baby sleeping bag are filled with glass beads.When gentle pressure is evenly distributed on the body it just likes your embrace. - Convenient double zippers our baby sleep sack comes with a 2-way zipper design that means you can easily access the bottom for midnight diaper changes.The sleep sack also includes zipper protection to ensures your little one s skin never comes into contact with the fasteners providing you with peace of mind. - Safety sleep the neckline has been carefully designed and tested multiple times to ensure a safe fit and prevent babies from slipping into the sleeping bag. The extra-long and roomy-in-the-leg design can allow your baby to comfortably move their legs and hips moreover sleeveless sleep bag is the best choice for an infant like to roll over or to their side.