When purchasing a PurpleAir Flex or PurpleAir Zen, it will no longer come with a micro SD card. The PurpleAir Classic SD sensor is not affected by this change and will still come with a micro SD card.
You are able to use your own micro SD cards with PurpleAir sensors. Information on doing this is available here: SD Card Logging and Troubleshooting.
To include a pre-formatted micro SD card with your sensor, you can add it to your order here: MicroSD Card (Formatted) – PurpleAir, Inc..
Links are also available on the PurpleAir Flex and PurpleAir Zen store pages.