The arms reach 16.4 inches from the wall and are 35.5 inches long, so the hull lies in the cradle rather than hanging from one point. Lashing straps tighten over the deck and loosen again for the next trip.
Fix it into wall studs in the garage, or into the posts of a dock where the boat lives for the summer.
You will work overhead or at the top of a stud wall, so set the ladder on a level floor, face it and keep a hand on it while you drive the screws. Fasten the brackets into solid framing (a joist, a rafter or a stud), never into drywall alone, and read the instructions in the box first.