HEALTHIER LIFE - Glass food containers are Eco-friendly, environmentally-safe, and food-safe non-toxic material; supports healthier eating and portion control by allowing you to meal prep ahead of time. EASY LUNCH PREP - Borosilicate glass is safe for baking in the oven, freezer storage, and reheating. Modular stackable design allows for neat packing in lunch bag or for storing leftovers in the freezer. LOCKING LIDS - Food prep containers with a 4 sided, bpa-free, secure-snap lid with rubber gasket ensures airtight seal for food freshness and 100% leak-proofability for mess-free transport on-the-go, to the gym, work, and school.