SmartLock® system features a tight, audible click closure that helps ensure maximum food freshness. Resists grease and moisture to preserve the flavor and consistency of food. Convenient food containers resist leakage. Microwaveable up to 250ºF (121ºC). Textured sidewalls allow for more secure handling. Conveniently stackable containers conserve storage space. Contains 40% average talc blended material.