True story: I only brought two pairs of this underwear to Europe for my 10-day trip, and I’m sure I would’ve been fine with only those two pairs for a much longer trip than that.
The general idea is that you wash one pair in the sink and let it dry while you wear the other pair. And then you switch and repeat. This underwear is super comfortable, odor resistant, and quick drying, so it works out great if you’re trying to conserve space for other things. You just need to remember to wash the other pair every night.