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On their website it gives the height at 8'7". Looking at the picture, it appears the roof retracts horizontally as opposed to sloping downwards. On that basis I would say that the air draft is the figure given.
Hi there , Just tried to look at this , found this on you tube , also tried to look closer at the helm area for measurement plate for height during film clip https://youtu.be/lALkahIUsOA Not clear photo when I tried to look