Zippers - multiple pulls
In zippered bags, the typical design is one or two pulls. With one pull, you know where the zipper is, because it’s at one end if it’s closed and the other if it’s open.
With two pulls in “X configuration” (pulls mounted end to end), the pulls are at each extreme when the zipper is closed and at one end or the other when the zipper is fully open. Or they’re somewhere in the middle if the zipper has opened mid-way. (This is related to how two zipper pulls on separating zippers, as in jackets, work.)
With two pulls in “O configuration” (pulls mounted head to head), the pulls are at each extreme when the zipper is fully open and they’re anywhere in the middle when closed.
A few backpacks like 5.11 and Outlier have pioneered “quad zip” configurations with a long zipper opening the top and the entire sides of the pack, where four pulls are mounted as two X configurations in sequence, with the middle two pulls forming essentially an O configuration in the middle. Thus, the outermost two pulls allow for quick side access to the pack, and are found at the two bottom sides of the pack when closed. Meanwhile, the middle two top pulls allow for top access to the pack and are generally found at the middle/top of the pack.