Durable, functional and oh-so-playful, our Mackenzie backpacks are packed with pockets, straps and gear loops to keep everything in place. Made of water-resistant recycled polyester and featuring adjustable padded shoulder straps, exterior straps to hold a Mackenzie lunch bag and exterior side pockets fitted to our water bottles, it's the most efficient and playfully designed collection around. Personalize it with their name or initials for a smart, extra-special touch. DETAILS THAT MATTER Backpacks Made of rugged, water-resistant 600-denier recycled polyester. Interior is lined with 150-denier recycled polyester. Yarn-dyed fiber has incredibly rich color that holds its vibrancy over time. All backpacks have adjustable PP webbing straps that are contoured and padded to ensure a comfortable fit; padded back panel adds extra cushioning. Features a YKK zipper closure with a Nickel finish. Exterior side pockets are designed to hold any of our water bottles (sold separately). Our glow-in-the-dark backpacks features a material that needs to “charge” under bright light for approximately half an hour to glow properly. Glow lasts for approximately 3 to 4 hours. The Glow effect will become weaker over time. KEY PRODUCT POINTS Pottery Barn Kids exclusive. Large backpacks are made of 86 units of 500ml recycled plastic bottles.