All Pumpkin car stereo can be expanded media choices by plugging USB flash drive into USB port. And you may want to change the USB speed to obtain faster rates between the quad core Android head unitand USB devices. Here's the instruction:

1. Enter the Setup -> About Device -> Factory Settings, and then enter the password (1234).



About Device

Enter the password

2. Click Others, then slide down the menu to change the USB speed settings.



Slide down the menu

3. After that, just click the Save. and you can see the info that you've changed.



Also, here's a video for reference: