Yes, all of our smartphones support up to 4G HSPA+21 Mbps speed.
New model with 4G LTE will be releasing shortly in 2015 Q4.
Make sure your device is turned off then remove the back cover. Remove the battery if installed. Locate the desired slot marked either 1 or 2 and insert the SIM card with gold contacts facing down and cut-off corner facing out. It will click into place.