When the Tbolt was released, it didn't include an LTE network switch. The LTE OnOff application was developed as a shortcut to a standard HTC testing menu. A LTE switch was later added to the phone mobile network settings. The CDMA only option in the phone settings is equal to the CDMA Auto (PRL) option in the LTE OnOff application. The LTE/CDMA option in the phone settings is the also the same option as the LTE/EDVO Auto option in the LTE OnOff application. The phone switches between 3G and 4G when the phone is left in the LTE/CDMA setting. CDMA Only is for 3G connections only.