T-Mobile is bringing back its 10Gigs4All promotion, offering of 10 GB of high-speed data on each of four lines for $120, the carrier announced Wednesday.

With the promotion, two people can get 10 GB of 4G LTE data each for a combined $100 per month and can add additional lines with 10 GB of data each for $20 per month for each additional line. The promotion essentially offers the fourth line of data service for free, for a savings of $20 per month.

According to the Un-carrier, customers will get to keep the $120 promotional rate for as long as they are a T-Mobile customer. As is standard on T-Mobile plans, each line will also include unlimited talk and text as well. Unused data from a given month can be rolled over for use up to a year later with the carrier’s “Data Stash” feature.

“After T-Mobile first introduced #10Gigs4All with the 4th Line Free this past summer, customers flocked to the Un-carrier, making this T-Mobile’s most popular promotion of all time based on the percentage of postpaid customers signing up,” the company said in a press release. “This once again takes direct aim at the carriers’ shared data schemes, punitive overages and hidden fees.”