There was no "universal" bumper when the iPhone 4 was released back in June 2010. When the Verizon iPhone 4 was released, thats when they started making the "One bumper fits all".If you go to the apple store there is no ATT or Verizon bumper. It's a universal bumper. I'd imagine if you got it really early then maybe it wasn't universal, but mine I had for the 4 worked with the 4S.