Google Chromecast with HD TV is specifically designed for teles that don't match up to 4K but still give a decent enough picture and resolution.
The All New Chromecast with Google TV HD Is Pretty Great For $29! Hands-On Review
Chromecast with Google TV HD review: Super simple 1080p streaming
Chromecast with Google TV HD Review: Raising the Bar - CNET
Google Chromecast with Google TV (HD) review: Super streamer, on a budget
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Chromecast with Google TV (HD) review: Lower resolution, lower price
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Google Chromecast with Google TV - Streaming Entertainment in 4K HDR - Snow GA01919-US - The Home Depot
Chromecast with Google TV (HD) review: Lower resolution, lower price
Chromecast with Google TV HD review: Super simple 1080p streaming