MAXIMUM 2 PER ORDER
Not that the 3in adapter doesn't have its own identity, but we've already summed up the time-slashing benefits of adding the adapter to your submersible dewatering pump in the 2in adapter description.
What's so special about the 3in adapter? It's 3 inches. And you need the 3in adapter for this guy: the 3in discharge hose. We know, it's not rocket science.