new Echo Dot 4th Generation design The fourth-generation Amazon Echo Dot speaker comes with a Voice Assistant Power Adapter. The Amazon Alexa app and wifi are needed for the easy setup. It is roughly 3.9 inches long and is made of half covered fabric and half plastic. Four physical buttons for turning on Alexa, turning off the microphone, turning up the volume, and turning down the volume are located at the top. The 3.5mm audio jack and power adapter for attaching your Echo Dot to a larger speaker are located on the back.