OutdoorMaster via Amazon offers its OutdoorMaster Sling Bag Backpack in four colors (Gray pictured) for $34.99. Coupon code "VLA8ZOTP" drops the price to $20.99. Plus, Prime members receive free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, it adds $6.48.) That's $14 off and the lowest total price we could find. It features an adjustable, padded shoulder strap; hidden anti-theft pocket; and measures approximately 19" x 12.5" x 4".