The network is provided by SK Telecom, one of the largest telecommunications operators in South Korea, covering the whole country
There are pick-up points at major airports in South Korea (Incheon, Gimpo, Busan Gimhae, Jeju, Daegu, Busan Port) and Seoul. You can pick it up immediately after arriving in South Korea.
Unlimited 4G/LTE data, multiple people can share the network and use it as much as you want