One piece construction makes these containers leak,Website:http://www.allpackingbox.com, and grease resistantEco friendly paper products are more envionrmentally friendly than plastics or styrofoamPerforated vents on the top tab can be pressed in to create openings to release steam, helping to keep fried foods crispyFour panel top uses inter-locking tabs to create a secture closureNested Stacking allows for easy storage, and makes it easy to grab from the stackChinese take-out boxes are made of polyethylene thin coated white paper board to make them perfect for hot solids as well many other uses. These are made with no wires and are therefore microwaveable.