Transit bags not only protect Your Engel Fridge/Freezer with a layer of insulation, but they also offer a heavy-duty foil layer on the inner side that reflects direct sunlight and long wave radiation. High quality gray canvas outer layer comes with an accessory pocket and vents. The bag covers the entire unit and is easy to open. Simply unzip the bag on top. The bags work with the corresponding transit slide locks. Breathing holes are built into the compressor to avoid overheating