MicroSD cards are tiny but slow; the M.2 storage sticks in your PC are blazing fast but bigger and fully enclosed. Now, a new type of SSD out of China could be the best of both worlds — and it’s already set to appear in two cutting-edge gaming portables.

Chinese storage manufacturer Biwin is calling it the “Mini SSD,” though another manufacturer refers to it as the “1517”; it measures just 15mm x 17mm x 1.4mm thick, smaller than a U.S. penny and just slightly larger than MicroSD. Despite that, it offers maximum sequential read speeds of 3,700 megabytes per second (or 3,400MB/s writes) over a PCIe 4×2 connection, and offers 512GB, 1TB and 2TB capacities.

To put that in context, the new MicroSD Express cards that work with the Nintendo Switch 2 top out at a theoretical 985MB/s, less than a third the speed. And while a full-size SD Express card could theoretically beat Mini SSD at 3,940MB/s, it would be nearly twice the size of Biwin’s creation.

The nano-SIMs used in recent smartphones are still smaller, though, and M.2 drives are still faster. I whipped up a quick chart so you can easily compare various storage cards and SIMs:

It’s not clear if Biwin’s Mini SSD is a true standard that other storage makers can easily adopt. But the company’s marketing it for laptops, tablets, phones, cameras and more, with its own dedicated slot that works exactly like smartphone SIM card slots: stick in a pin to remove the tray.

The company claims IP68 water and dust resistance, which could be handy for phones in particular, and three-meter drop resistance.

Two cutting-edge Chinese gaming portables already appear to be customers, both of which made announcements at ChinaJoy this past week. There’s the GPD Win 5, the monster battery backpack wielding Strix Halo handheld we told you about in July, which you can see with the new SSD in the video atop this story.

We don’t have any idea of pricing on these new SSDs, and have seen no product listings for them yet.