On Thursday, Sprint, the nation’s fourth-largest wireless carrier, announced a new unlimited data plan that costs just $15 per month—the lowest on the market, even less than pre-paid carriers. The deal, which kicks off June 8, will be available for a limited time only online and by phone, but not in stores.

The promotion will “last weeks, not months,” Allan Samson, senior vice president of acquisition for Sprint, told Cnet.

The get-it-while-it’s-hot deal is just one of the several pushes by Sprint to lure new customers since its $26 billion proposed merger with T-Mobile and the introduction of its new CEO, Michel Combes.

A year ago, Sprint shocked many with its limited-time offer of one year’s worth of free unlimited data to all new customers with eligible phones. This latest promotion seems to have upped the discount ante for rival wireless carriers.

However, Sprint’s $15 plan comes with a catch. While it covers unlimited calls, text, and 4G LTE data, the deal caps video streaming at a low 480 pixels. So, Netflix lovers may not be able to binge-watch their favorite shows from their smartphones anymore—at least with much screen clarity. Additionally, the $15 rate is probably going to be a little higher than marketed because the promotional price is calculated without adding any of the usual taxes and fees.

Perhaps it’s most notable drawback is that the plan requires a new line port, meaning customers must bring their number from another carrier.