The RV50X is an industrial 4G LTE cellular gateway that provides serial and Ethernet connectivity to numerous cellular networks. (The RV50X automatically falls back to 3G when 4G coverage is not available.) The RV50X is capable of  4G LTE, 3G HSPA/HSPA+, and 3G TD-SCDMA (Asia Pacific model only) networking and is carrier-approved worldwide for Verizon, AT&T, T-Mobile USA, Rogers, Bell, Telus, and other cellular data carriers. The networking and carrier used by the RV50X are determined by the active SIM card(s) inserted into the device. Note: The RV50X does not ship with a SIM card unless the cellular modem was provisioned with/for Cellular Data Services; the SIM card is provided by the carrier when signing up for service.