Sizer bin tested to fit in the overhead bins of most major domestic airlines while allowing for more packing capacity. 8 Spinner wheels rotate 360, providing superior maneuverability and a smooth glide in every direction Low profile top and side carry handles along with bottom grip provide multiple carrying options. Roomy main compartment expands 2 to maximize packing capacity when needed Lightweight, 100% Polycarbonate hard shell is engineered for impact-absorbing flexibility with a stylish outer finish that helps reduce visible scratches and scuffs. Built-in lock allows TSA authorities to safely unlock and relock the bag for inspection when needed (default code set at 0-0-0)