Corrugated plastic. Patent pending design makes transporting bottles and other lab essentials safer and easier. NALGENE 4-in-1 EZ Tote is versatile, durable and lightweighing. Pre-assembled partitions are included and assembly instructions are printed on each tote. Recommended for temperatures from refrigerator to room temperature. Do not autoclave. - Carries 8 x 500 ml, 6 x 1l or 2 x 4 l bottles. - Holds up to 12.7 kg. - Easy to assemble and stores flat. Corrugated plastic. Patent pending design makes transporting bottles and other lab essentials safer and easier. NALGENE 4-in-1 EZ Tote is versatile, durable and lightweighing. Pre-assembled partitions are included and assembly instructions are printed on each tote. Recommended for temperatures from refrigerator to room temperature. Do not autoclave. - Carries 8 x 500 ml, 6 x 1l or 2 x 4 l bottles. - Holds up to 12.7 kg. - Easy to assemble and stores flat.