Li'l Hummer II / Sierra BackPack 103243 or Li'l Hummer XL / Everest BackPack 103218 or ..The Sierra Back pack commercial power in a backpack vacuum weighing only 9 lbs.! The versatile design allows you to use it as a canister, too. With an optional power nozzle attachment by O reck, the Sierra is a favorite of commercial maid services everywhere.