Add a second layer of plastic on your tunnel and inflate it and it will increase your temperature in cold weather by 2-3 degrees and it will eliminate loose, flopping plastic which means longer roof life. Comes with poly blower and mounting bracket.
All the bolts, connectors, and metal to turn your normal bow into a W-Truss. May be done on every bow or every other. Count the number of total bows and subtract 2 to get the quantity needed or the inside exposed bows. You may choose to do every other one.