BETTER INSULATION: These excellent fashioner 12" lunch sacks are made of thicker 5 mm rock solid neoprene, which keeps your nourishment pleasantly chilled up to 6-8 hours. ... NON-TOXIC AND PVC-FREE: Your lunch packs are 100% safe, for you, your children and for nature. Additionally, both are launderable, reusable and foldable for simple stockpiling.