Percolator is just an elitist way of saying thing that forces liquid into one end of a solid, such as coffee or tea, and out the other as a way of steeping it. But Bialetti probably felt it sounded more sophisticated and legit to call this duo of espresso shot makers a stovetop percolator than, like, a stovetop caffeine enema.
Bialetti's percolating spouts stream out 2 cups of Italian espresso in 4 to 5 minutes. The device's base fills with water (up to the height of its copper bolt) and sits directly on top of a range burner. Once the water begins to boil, it filters up through a scoop of espresso inserted above the percolator's base, with fresh coffee then pouring out the spouts.