$68.99 USB 5V to 12V 4.0x1.7mm Power Supply Cable for Echo Dot 3rd Router LED Speaker|Data Cables 
2 Pack USB Charger Cables for Echo Dot 2nd Generation, Tap Alexa Enabled Portable Bluetooth 
Amazon Alexa Echo Dot gen 1&2 replacement USB Charging Cable Power Lead 1 metre | eBay
