T-Mobile US, Inc. is a provider of mobile communications services, including voice, messaging and data, under its flagship brands, T-Mobile and Metro by T-Mobile in the U.S., Puerto Rico and the U.S. Virgin Islands. Co. provides mobile communications services primarily using its 4G Long Term Evolution (LTE) network and its 5G technology network. It also offers a selection of wireless devices, including handsets, tablets and other mobile communication devices, and accessories for sale, as well as financing through equipment installment plans (EIP).