How to Match a CFexpress Reader to Your Camera's Card Type

By The Camera Exchange | Published: 2026-10-31

Category: How-to Guides

Learn how to match a CFexpress reader to your camera's card type, avoid USB-A bottlenecks, and set up a reliable dual card reader workflow for faster transfers.

Quick answer

Identify the exact card type your camera writes—CFexpress Type A, CFexpress Type B, or SD UHS-II—then choose a reader that supports that slot and connects through USB-C for the fastest transfers. If your computer only has USB-A, use a USB-C-to-USB-A adapter or cable and expect lower real-world speeds.

Why card type comes before reader brand

CFexpress Type A and Type B cards are physically different and not interchangeable in a reader. A reader labeled only for Type B will not accept a Type A card, and a Type A slot will not take a Type B card. SD UHS-II cards use a different connector again. Before comparing prices or transfer speeds, confirm the exact card model printed on the card or listed in your camera menu.

Many cameras have two slots with different formats—for example, one CFexpress Type B slot and one SD UHS-II slot. In that case a dual card reader lets you offload both cards without swapping devices, which is the core of a practical dual card reader workflow.

USB-C is the fast path, USB-A is the compatibility path

A CFexpress Type B card reader with USB-C is the typical way to reach the card's higher transfer speeds, but only if your computer port and cable also support that speed. Plugging the same reader into a USB-A port through an adapter usually works, but the connection may run at a lower speed. That is a compatibility trade-off, not a defect.

Check whether your computer's USB-C port supports high-speed data transfer or only charging. A charging-only port will not deliver the fast transfers you expect from a CFexpress reader.

When a dual-slot reader saves time—and when it doesn't

A dual card reader is most useful if you regularly shoot with two card types or want to ingest a CFexpress card and an SD card in one pass. If you only ever use one card type, a single-slot reader may be smaller and cheaper, but it will not simplify a two-card workflow.

Dual readers also add a second slot that may not match your fastest card. Confirm both slots support the formats you actually use rather than assuming any dual reader covers CFexpress Type A and Type B together.

Step-by-step: match your reader to your card

Identify the exact card type in your camera: Check the card label or your camera's card-slot menu for CFexpress Type A, CFexpress Type B, or SD UHS-II. Write down each slot's format if your camera has two slots. Do not assume all CFexpress cards are the same size; Type A and Type B require different readers.
Choose a reader with a matching slot: Select a reader that explicitly lists the card type you identified. For a camera with both CFexpress Type B and SD UHS-II, a dual reader with those two slots avoids swapping devices. A reader that lists only one CFexpress type will not accept the other.
Confirm your computer's port and cable: Use a USB-C port and a cable rated for data transfer, not a charge-only cable. If you must use USB-A, connect through a USB-C-to-USB-A adapter and expect lower transfer speeds. Test the cable with a known fast drive before blaming the reader for slow transfers.
Run a short transfer test before a big shoot: Copy a small folder of files from each card type and note the approximate speed. If one slot is much slower, check whether the card, cable, or port is the limiting factor. A slow result on one slot does not always mean the reader is faulty; isolate the variable first.
Set up a repeatable offload routine: Label which slot corresponds to which card, copy files to a named folder, and verify the file count before formatting the card in camera. Never format a card until you have confirmed the copy on your computer.

Product facts

ProMaster Dual Card Reader – CFexpress Type B & SD UHSII – USB-C & USB-A: Dual card reader with CFexpress Type B and SD UHS-II slots and both USB-C and USB-A connections. It covers the two most common card types in one device and gives you a USB-A fallback if your computer lacks USB-C.
ProMaster Dual Card Reader – CFexpress Type B & SD UHSII – USB-C & USB-A