From the TrueLock Collection. TrueLock locking lid containers offer easy 4x heavy-duty locking lid hinges to secure the lids to the base. Prep, bake, preserve, transport, serve and reheat, the lids offer easy view storage, organization and transport of food items and leftovers. These tempered glass containers are oven, microwave, dishwasher, refrigerator and freezer safe. The lids are designed to lock on the lid on the container and are leakproof when used as intended. Lids are intended for microwave use only for reheating purposes and storage in the freezer and refrigerator.