frame rucksack
frame backpack

The original product was an external frame rucksack.

"Oh, I wouldn't say that, Ma'am," the valet answered, adjusting the straps of the internal frame rucksack which, along with the chameleon suits they both wore, had come out of the company's spare stores.

Before I can summon up some energy, we've parked near the Old Dungeon Ghyll and Gordon is hoisting a huge frame rucksack onto his back, packed with his Hasselblad medium format camera and various other photographic gizmos.