Comcast announced a $5-a-month streaming video service Thursday called Xfinity Flex , an offering that aggregates on-demand video from your subscriptions like Netflix Amazon Prime Video and HBO, as well as offering free ad-supported shows to watch and options to rent and buy programming. From a report:Xfinity Flex comes with a 4K and HDR-ready wireless set-top box with an X1 voice remote, Engadget adds . It's scheduled to launch March 26th, and will be available to customers who have Comcast internet.