Writing this review to confirm that this pump fits perfectly with the Drinkwell 360 water fountain! The original pump casing melted (!) after using too hot water to clean it - so I had to find a replacement. The original manufacturer's part retails for almost three times the price of this pump. Go for it, it works!
Good to know: it is ever slightly noisier than the original pump that came with the fountain. No idea why. You also must use the included power adapter, as the wiring is different from the Drinkwell one.