“This is a change to the plug at the end of the cable and this is not compatable with earlier Pi models. In the past I have used Ipad charges for earlier Pi's that I still have running and although they max out at 2.5V the ease of removing the usb from the PSU at teh PSU end is great. They were also interchangeable. Now with teh new Pi 4 I have to buy a new PSU each time. :-(”