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Sea to Summit says:
Our Pack Racks are a soft inflatable roof rack engineered for simple installation and compact transport.
Their compact packed size makes them perfect for stowing in your bag and transporting boards, boats, skis and oversized gear when you’re travelling and hiring cars.
Conveniently stowed under your car seat, they are also great for unplanned purchases at the hardware store.
Sea to Summit’s multi-function Airstream™ Pumpsack comes standard with every Pack Rack. The high quality Ultra-Sil™ stuff sack stores your racks when deflated, the integrated Airstream™ Pump aids easy rack inflation and it can also be used as a projected load caution flag.