We’ve seen a handful of accessories designed to expand the internal storage of a MacBook through the SD card slot. Generally, they’re adapters that work with self-provided microSD cards, but PNY has a different take: the StorEDGE Flash Memory Expansion Modules ($100-$200) are trimmed down SD cards that don’t require any other pieces.
Coming in 64GB or 128GB capacities, StorEDGE can double the space in a base-level MacBook Air. The module plugs right into the SD card slot, but instead of sticking halfway out, there’s just a small ridge. It’s enough to pull the card out when necessary, but not so much that you have to worry about it getting caught on anything. That extra space is useful if you’re working with a lot of media, or just want an internal Time Machine backup.