The most efficient way to carry multiple kayaks. Four boat maximum capacity. Tying boats down is easier than ever with the upper bridge design. Easy carrier transfer from vehicle to vehicle with proven universal hardware. For a clean look when in use, the stacker folds down flat. Fits Thule standard, Rapid Aero, Xsporter bars, Yakima, and most factory installed installed racks. Includes one pair ratcheting tie downs, two straps, and buckle protector.