a1533 how to know model gsm or cdma

On the Apple 5s tech specs page, there's an asterisk next to A1533. At the bottom of the page, the asterisk reads: "To identify your Apple iPhone model number, see http://support.apple.com/kb/HT3939." Model A1533 is available in either GSM or CDMA configuration.

You can check the Apple website for the various models and specs. You can also use Google.