Just as the Department of Justice begins examining whether the proposed merger between T-Mobile and Sprint would raise wireless prices for US consumers, Sprint is announcing a limited-time unlimited data plan for $15 per month. If you can put up with 480p video when using cellular data and don’t mind potentially being slowed down during times of network congestion, $15 is pretty cheap. Sprint’s regular unlimited data plan is $60 per month.

This promotional plan includes unlimited talk, text, and data. It does not include any hotspot functionality whatsoever. It launches tomorrow, June 8th, so if you’ve got specific questions around what else might be included (international data, etc.), they might have to wait until the full details are out. The other big asterisk is that this special offer requires porting a number from another carrier. You can’t just start a new line of service. So you’re not exactly making a small commitment by going in on this.

Sprint is only offering the $15 deal online or by phone, so it’s not something you’ll be able to get by walking into your local store. You’ll also be paying additional monthly fees and taxes, so don’t expect a flat $15 bill. And customers must set up and pay via autopay if they want that $15 price.

Sprint is emphasizing this plan won’t be around for very long. The carrier told CNET that it will be available for “weeks, not months.” Presumably once you’ve signed onto the plan, Sprint will let you keep it until, well, who knows exactly when.

How appealing this offer is really boils down to Sprint’s network performance in your area. To that end, Sprint claims that its national average download speed increased 34.5 percent year-over-year from May 2017 through May 2018. Here’s the coverage map.