Our eco-friendly and patented, Take-Out Now, hinged to-go containers are made from polypropylene and a natural mineral powder. The addition of this powder greatly reduces the amount of plastic polymer in the finished product and yet increases it's overall strength and rigidity. This hybrid material is microwave safe and can withstand high heat! An excellent 4-snap closure system. Never a worry about the lid popping open! It's simply the best to-go container on the market today!