Hardside (Polypropylene) shell material is made of injection molded polyproplye, a highly impact-resistant plastic that is strong, lightweight, flexible, and moisture resistant. Wide-Track wheel system features large shock-absorbing wheels mounted near the outside edge of the case for easy rolling, maneuverability, and stability on a wide variety of surfaces. Push button retractable handle locks when fully extended so you can push or pull your case. locks when fully recessed, greatly reducing the risk of damage when not in use. Cross straps/ Tie tape secure the contents of your