Can I use a charging cable from Amazon instead?
No, very unlikely it will be compatible and it could damage the circuitry by applying current to the wrong lines. Please only recharge with the official USB to 2.5mm charging cable.
Official Vagus.net tVNS Stimulator Charging Cable. USB to 2.5mm Charging Cable for VagusNet tVNS Stimulator
|10 × 5 × 1 cm