Your phone’s data speed can vary depending on your plan, physical location, local cell towers, and many other factors. If you’re on AT&T, there will now be one more variable in the mix: a new ‘Turbo’ add-on that claims to boost speeds.

AT&T just announced Turbo, an optional-add on that aims to provide “enhanced data connectivity for real-time responsiveness and improved stability.” It costs an extra $7 per month on top of your usual AT&T phone plan, and it’s available starting today.

AT&T said in a blog post that Turbo is “Built to support high-performance mobile applications, like gaming, social video broadcasting and live video conferencing, with optimized data while customers are on the go. AT&T Turbo allows users the choice to optimize their network when they want by adding additional network resources to their mobile data connection.”

The company didn’t mention any specific details about how it works, including if mobile plans without Turbo are now deprioritized in favor of plans with Turbo. AT&T and other carriers already use varying priority levels based on the customer and device type, called Quality of Service Identifiers (QCIs), since cell network capacity is fixed in any given area. For example, phones on a T-Mobile NVMO (like Mint Mobile) wouldn’t get the same priority level as a phone on one of T-Mobile’s own unlimited plans.

The Mobile Report theorized that Turbo might just bump up plans to the next QCI level, especially considering some AT&T customers were recently bumped down a tier. AT&T denied that in a statement to The Verge, saying, “Although AT&T Turbo currently is assigned to a QCI to which some of our consumer traffic previously was assigned, we’ve materially modified it and increased network resources and relative weighting for AT&T Turbo traffic, thereby creating a higher level of performance than we’ve ever before offered to consumers.”

Unfortunately, Turbo won’t let give you faster speeds and improved connectivity on AT&T’s prepaid plans or other lower-tier plans. It’s only available on the Unlimited Premium PL, Unlimited Extra EL, and Unlimited Elite plans—the cheapest one there is Unlimited Extra, which already costs $50.99 per month for one line.

Source: AT&T, The Verge, The Mobile Report