YouTube TV is today revealing more details about two anticipated new features: 4K playback and offline downloads. As it turns out, the service will be bundling them together in a new add-on package it’s calling “4K Plus.” There’s no getting one without the other.

4K Plus is available starting today and will cost an extra $19.99 per month on top of the standard $64.99 YouTube TV subscription. That sounds awfully expensive, but at least there’s this: customers will receive a free one-month trial — and if you sign up early, 4K Plus will be discounted to $9.99 each month for the first year. That’s easier to swallow than $20, but you’ll eventually be shifted over to the full price once that initial promotion expires. So for the first year, you’re looking at a $75 monthly bill, and $85 if you keep 4K Plus after that. Add in taxes and fees and, well, ouch.

For now, offline downloads will likely be a bigger deal for many customers than 4K streaming. Outside of select sporting events, there’s still a dearth of 4K content on network and cable TV. (For that reason, some competing services like FuboTV don’t charge extra for 4K streams.) YouTube really isn’t in any position to solve that dilemma, but it’s promising that 4K Plus subscribers will be able to “watch major sports events this summer in 4K, plus live content from networks like NBC, sports like college football and basketball later this year, and on-demand content from FX, Discovery Networks, Tastemade and more.” You can search for “4K” to see all available 4K programs. YouTube TV is also preparing for the Olympics with new features that will let you quickly jump to specific sports or moments of an event without having to manually scrub through.

When asked whether offline downloads will face any channel or content restrictions, YouTube told me that anything recorded to your cloud DVR from the base channel package can be downloaded to YouTube TV’s mobile app. So in theory, you shouldn’t run into any frustrating limitations or channels that block the feature. I’d hope for as much considering the price! However, the company noted that some premium network add-ons might not allow offline downloads.

At least among streaming TV services, offline viewing is a rare convenience. Sling TV doesn’t offer it, and Hulu only supports offline downloads from its on-demand library of shows and movies. In the case of YouTube TV, you’re actually pulling down the entire DVR recording as it originally aired, so this approach is somewhat unique and Tivo-esque. YouTube told me that customers will have full control over playback, and rewind / fast-forward should work without issue.

Adding 4K Plus to your account also enables “unlimited” concurrent streams for any devices that are on your home Wi-Fi network. YouTube TV usually limits customers to three simultaneous streams, and this will still apply for devices that are outside your home.

Dolby 5.1 surround is coming to YouTube TV

In welcome news for all YouTube TV customers, the service will also be introducing support for Dolby 5.1 surround sound “soon.” And this doesn’t require any special plan or add-on. YouTube says 5.1 audio has consistently been among the biggest feature requests from subscribers. It’ll be rolling out to “select devices” over the coming weeks. Smart TVs are first on the list, with other platforms to follow in the near future.