Le Creuset Tri-Ply Stainless Steel Stockpot with Lid and Deep Colander Insert, 9-Quart VENT-Designed to mimic the functionality of cast iron, the vent controls the flow of steam, keeping the lid securely in place while cooling SIDE-WALL-Tri-ply construction features a full aluminum core with a magnetic exterior side-wall that is compatible with induction stovetops MATERIAL-Finished with a radiant luster, the proprietary blend of professional-grade stainless steel resists oxidation and discoloration over time KNOB-Made for easy gripping, the stainless steel knob is safe to 500 Degree F Lifetime Limited Warranty