The TamperAlert™ tab sticks up when torn and, with the "Do Not Purchase If Tab Is Torn" message on the lid, lets customers know when the lid has been lifted. The 360° VanishingEdge™ Seal inhibits lifting the lid from the base without tearing the tab. It also provides a leak-resistant seal that maintains freshness. This crystal-clear, stackable lid offers a safe way to feature bistro boxes, salads and endless snack combinations.