Elecom has released the MR3C-D21BK, a direct-plug memory card reader that carries a USB-A plug and a USB Type-C plug on a single body, with sales starting in early July 2026[1]. It has separate slots for SD and microSD cards, and both can stay inserted and be read at the same time. The aluminum housing measures about 9mm thick and weighs roughly 13g, aimed at people who want to move camera footage straight onto a smartphone[1][2].
Two-way plugs for laptops and phones alike
The MR3C-D21BK places a USB Type-C plug on one end and a USB-A plug on the other. It connects directly to a USB-A port on a PC or a USB Type-C port on a smartphone or tablet without an adapter, so one unit covers both sides of a typical transfer[1][2].
Both plugs run at USB 5Gbps (USB 3.2 Gen1). No dedicated driver is required, and the reader is recognized as soon as it is plugged in. Supported operating systems are Windows 11 and 10, macOS Sequoia 26, iOS 26, iPadOS 26, and Android 16, 15 and 14, covering the major platforms[2].
Both cards stay in, and card-to-card copying works
There are two slots, one for SD and one for microSD, and they can be used simultaneously. Beyond pulling files from both cards to a PC in one pass, users can move data directly from one card to the other. For workflows that bounce between an SD card in a camera and a microSD card in an action cam, that cuts down on swapping[1].
Transfer speed follows UHS-I at up to 104MB/s in theory. UHS-II and SD Express cards can be read and written as well, though throughput in those cases stays at UHS-I levels[1][2]. Elecom says the design stabilizes data quality between the PC and the reader based on measurements from certification testing of transmit and receive signals, in order to limit compatibility problems with connected devices[1].
One caveat: the SD card lock function and copyright protection features are not supported, which is worth checking before buying[2].
Aluminum body with a cap and strap included
The housing uses aluminum for heat dissipation and noise resistance. Dimensions are roughly 17mm wide, 69mm deep and 9mm high including the cap, with a weight of about 13g. The stick shape fits into a bag pocket, and an access lamp shows when media is being read or written[1][2].
A cap that keeps dust out of the connectors when the reader is idle, plus a strap for loss prevention, are both included. The body has a strap hole, so users can swap in a strap of their own[1]. The product also carries Elecom's THINK ECOLOGY mark, meeting the company's internal environmental criteria with packaging made only of paper, cardboard and poly bags[1].
Price and availability
The model number is MR3C-D21BK and the JAN code is 4549550443128. The press release lists a street price of 2,481 yen, or 2,255 yen before tax[1], while the standard price shown on Elecom's product information page is 3,817 yen including tax[2]. The warranty period is one year[2].
Listed sales channels include Biccamera.com along with the Elecom Direct Shop main store, its Rakuten Ichiba store, and its Yahoo! Shopping store[1].
Summary
The MR3C-D21BK pairs two-way USB-A and USB-C plugs with simultaneous use of SD and microSD slots, landing squarely on the practical side. Speed tops out at UHS-I, but being able to plug into both a PC and a phone without carrying an adapter, at around 13g, matters when footage needs to move right after a shoot. For anyone regularly shuttling files between a camera and a smartphone, it is the kind of accessory that can simply live in a bag.
Source: https://prtimes.jp/main/html/rd/p/000001469.000026881.html
