Perforated break-away hinge allows for easy separation of the lid from the base for one or two piece applications. Black base, clear lid accentuates presentation of your food. Anti-fog vented lids resist fogging and are vented to reduce condensation, allowing for a clear view of your product. Perimeter seal helps to avoid spills and makes a leak resistant seal. Durable and crack resistant material. Polypropylene is a tough material that is heat lamp, warming unit, and microwave safe. Open clamshells easily nest.