This step up is compact inside its dedicated bag, opens up cleanly to fit snugly over our SUV tire. By placing one foot on this step and my other foot inside the rear door step of our vehicle, I kept good balance and easily adjusted the Thule GoPact bags up into/out from the cargo carrier. Securing the bags with the straps inside the cargo carrier was a cinch, too.
It would be awkward to hoist bags without this step.
You really should buy this accessory. It is well made and folds expertly into the Thule bag, too.