All handhelds will have a microSD card reader which the card will install in a tray as if there was a SIM? card to install. All cellular handhelds will use eSIM?, so the tray is exclusively for the card reader. If your card is not U3 or better standards, the handheld will warn you of the weaker performance, and caution you on loading higher demand files such as HD videos. Senitrus will only sell U3 or better cards. The W and A lineup will support 2TB? cards. The P series will be able to support SDUC which is not available yet, but the standard can go to 128TB. I would imagine the next new capacity will be an SDUC 4TB card.