Paper Cold Cups Feature A Wet Wax Coating That Is Perfect For Heavier Applications Such As Milkshakes Or Smoothies. Plus, The Wet Wax Coating Offers Superior Rigidity As Compared To A Double-Side Poly Cup. Cups Are Designed For Solo 7 Oz. Polystyrene Flat Lids With Straw Slot And Identification Buttons (Sold Separately).