This 15-1/2” bag is for the luggage rack and has 1 outside snap pocket 9-1/2" in diameter, 2 hidden pockets on each end, additional straps for attaching extra stuff like bedrolls, jackets, etc., and has a reinforced carry strap. 

• Outside Snap Pocket
• Two Hidden Pockets On Each End
• Additional Straps For Attaching Extras
• Reinforced Carry Strap
• Measures 15-1/2”