Big Rock Flexx BagCarry All Extra Large Packable Backpack for Women and Men. You've never seen a Carry All bag like this one. Up until now, there hasn't been a very convenient way to carry everything on your back: Luggage, duffle bags, Equipment, Car Seats, and more. This Stretchy, Heavy Duty black backpack fits all your heavy and awkward bags and odd shape sports equipment in one load And because of its 4 Way Stretch, it also is the Best Car Seat Travel Bag around.