You probably have a general idea of which iPhone you have—iPhone 6, SE, 4s, X, and so on. But behind the marketing names, each iPhone configuration has its own model number. You normally won’t need to know this number, but it could come in handy if you ever need to get more technical details about your device. Here’s where you can find your iPhone’s model number—and what that number means.

Which number is which?

Apple uses two numbering schemes for its devices. The first, which we’ll call the “A” number (hat tip to The iPhone Wiki for the name) is a five-digit alphanumeric string that starts with the letter A followed by four numbers.

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