Amazon Echo (2nd gen) review: smaller and cheaper, but mostly the same - The Verge
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All New Amazon Echo 2nd Generation 2017 Oak with improved sound powere – JG Superstore
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