Thermoformed using Polar's proprietary blend of high-impact polystyrene, Polaronde is built for strength and performance. The unique outer rim design (Square on the outside) is not only aesthetically appealing, but also allows for quick and easy separation, a tight lid fit and a generous surface areas for carrying hot meals without spills. The glossy china-like and satin-finish bottom make Polaronde cut and leak proof while preventing slips on table tops or trays.