6".
All my gadgets are USBC and I have two USBC Powercore.
I just handed Amazon Basics £10 for two cables.
I’m currently using the Type A to C 6" from “Cable Creation” with my Powercore 10000 PD Slim. The cable recently began to fail, I have to move it a few times to work. I’m out biking for a few days and recharge the 10000 PD Slim overnight