The SIM card in your iPhone is crucial to your making calls, but it’s also small enough to lose, and easy enough to put in the wrong way. Here’s how to successfully remove a SIM card, and put one back.

At least when SIM cards first came out, they were embedded in plastic that was credit card-sized and hard to lose. As the subscriber identity module became more common, and as phones needed have more components packed inside, the circuitry part stayed roughly the same, but the enclosing plastic shrunk to almost nothing.