【Fine Grid Is Upgrade Version】Upgrade 1: Mute spinner wheels of the suitcases are upgraded to METAL Bearing mute Spinner wheels, which is more solid, durable and labor saving. 【Fine Grid Is Upgrade Version】Upgrade 2: Luggage Zippers are upgraded to Double layer explosion-proof zipper. 【Fine Grid Is Upgrade Version】Upgrade 3: Wheels seats are upgraded to FIT wheels seats. 【Fine Grid Is Upgrade Version】Upgrade 4: The hardshell luggage surface has changed from frosted to fine grid, make it look more neutral. 【Fine Grid Is Upgrade Version】Upgrade 5: The angle design is a little different, make it look more neutral. mixi luggage is crafted from 3-layer Bayer PC, a key feature of this material is it has good compression resilience, strong and durable. And special surface treatment can hide scuffs and scratches, and is much longer performance life than the traditional luggage.