CalPak Ranger Rolling Backpack:
This 21" rolling backpack comes with a 16" detachable backpack. The bag is constructed from 1680 D. ballistic nylon with Diamond Tech trim. It has a single-pole handle system, heavy-duty in-line skate wheel system, and padded wheel covers. The bag also features an extension bottom pocket system, adjustable center strap, and padded top and side grip handles.