Which Echo Is Right for You? a Breakdown of Amazon's Smart Speakers
Amazon.com: Made For Amazon, Battery Base in Black, for Echo (4th generation). Not compatible with previous generations of Echo or Echo Dot (1st Gen, 2nd Gen, or 3rd Gen). : Everything Else
Best Buy: Amazon Echo (2nd Gen) Smart Speaker with Alexa Charcoal Fabric B06XCM9LJ4
Echo Dot 2nd Generation Setup Instructions - Tom's Tek Stop