What to Check When Buying USIM at Airport or Locally

TL;DR

• Buying local USIM at the airport: Counters and kiosks in arrivals; have passport and sometimes address ready.
• Pros: Often cheap for large data/long validity; no eSIM support needed. Cons: Queue, may need to remove home SIM (lose home number on that device), language/setup (APN) yourself.
• eSIM alternative: Install before departure, use data on arrival—no airport queue. See eSIM vs local USIM, Compare plans.