You can choose 4G/LTE Unlimited data only package or data+voice/SMS package,After inserting the SIM to your mobile, the left plastic card is the T-money public transport card (charge is required),If you choose data+voice/SMS plan, voice/SMS top-up fee will be charged when you pick up at LG U+ counter in airport (cannot be changed to data only plan at the counter),Please double check if your phone has carrier or country lock before booking. Phones with carrier or country lock cannot use the SIM cards.