The linen baby carrier has several advantages. It is thermoregulatory, cool in summer and retains heat during the cold season. Linen is a natural, durable fabric that breathes very well. The linen baby carrier has the advantage of being able to absorb up to 20% humidity without appearing wet. Our preformed bags offer 3 carrying positions: front, back and hip. They are not designed for ergonomic carrying when facing the world. We favor hip carrying which allows baby to look at the world when he is awake, but when he is tired, he can rest his head against the carrier. Our preformed products have passed several tests to guarantee their safety. Our preformed baby carriers are all certified ASTM F2237-16a. In addition, they have passed tests to certify the structure, fabric and flammability. All our fabrics are certified OKEO-TEX and without toxic substances. The foam in our preformed products is antibacterial and anti-mold. EVOLUTION (ADJUSTABLE) - 8 to 45 lbs Seat width: Adjustable from 5 to 16 inches (12.7 to 40.6 cm) Deck height: Adjustable from 11 to 19 inches (28 to 48.3 cm) Belt width: 5 inches (13 cm) Maximum belt length: 57 inches (145 cm) Notes: The Gustine Evolution is a fully adjustable baby carrier. It allows you to change the height and width of the carrier as your baby grows without having to use a booster seat.