Heys America Stratos Hybrid Deep Space 21" Carry-On Spinner (One Size, Red) Unlike the traditional 50 / 50 split in most luggage, the Deep Space System is designed with an increased back panel depth for easy and convenient packing Lightweight hybrid design combines the strength and support of a hardside luggage with the convenience and functionality of softside pockets 360 spinner wheels allow for effortless motion in different terrains Diamond embossing on hardside surface helps prevent surface scratches and scuff marks Zipper-released expansion system allows for an extra 20% in packing capacity