1.QC4.0 is only available in type c to type c port and need QC4.0 supported Cable, USB port just support QC3.0.
2.When charging two devices,it will be like normal charger

Material: ABS+PC

Output:

--Type-C: 5V/3A，9V/3A，12V/2.5A,20V/1.5A(Support Quick Charge 4.0& PD 3.0 Fast Charger)

--USB 1: 4.5V/5A,5V/4.5A,9V/3A,12V/2.5A(Support Quick Charge 3.0/FCP/SCP/AFC)

--USB 2 : 4.5V/5A,5V/4.5A,9V/3A,12V/2.5A(Support Quick Charge 3.0/FCP/SCP/AFC)

--USB+Type-C: 5V/5A Max(At Same Time)

--USB1+USB2 Output: 5V/5A max(At Same Time)

Input: DC 12V-24V

Function:

--PD 3.0 Fast Charge For iPhone X Xr Xs Xs Max

--Supercharge For Huawei P 30 Pro P20 Pro Mate 20

--Quick Charge 4.0 For Xiaomi Redmi Note 7 Pro Mi 9 etc

Note:This car charger does not support OPPO/vivo/OnePlus mobile phone fast charging