Just hang the strap onto the tray table! With a compact and easy to carry It is small, portable and light to carry around and easy to hang on the bag or fold up in the backpack and luggage case without taking too much space or adding too much weight This footrest helps prevent lower back pain, stiffness and leg swelling suffered during a long flight, let your legs just gently sway with the motion of the plane. Simply hang it on the arms of the tray table and place your feet in the footrest. Enjoy it with the tray table up or down. The adjustable straps allow for the perfect length to provide the necessary support.