The Leopold FC660C is not a new keyboard in itself, having been in the market for the better part of a decade now. Continual updates to the keyboard while retaining the same design have kept it relevant. For example, as of the time of this review, there are three color options and two switch options for the FC660C, but they all are under different names and SKUs. I have here the FC660C using the newer Topre Silent 45g switches, hence the low noise marking on the box and the product name itself. In addition, this sample uses the Leopold PBT dye sub keycaps for these Topre switches, which come in a two-tone color scheme different from the blue or black color options. All of these are not immediately reflected on the packaging, where we see the company and product name in large font printed on the front, and the distinguishing features spelled out on the right with supporting renders. More marketing features, specifications (including a typo), and even a full keyboard render greet us on the back, with further specifications on the side that also confirm that we have the English language version inside. A seal on either side combined with a flap keep the inner box in place, which you need to remove from the outer sleeve to access the actual contents.
This inner box is plain black cardboard with nothing to see aside from the double flap on the side that keeps the contents in place during transit. Opening the box, we see the keyboard right away inside a plastic wrap, and a multi-language quick-start guide above it. Covering the basic functionality and layers pre-programmed on the FC660C, it will aid users who can read Korean, English, and Mandarin in making the most of the keyboard in its default state, as it ships.
There is cardboard all around the keyboard for protection, including at the bottom, where we see a second layer which opens up to reveal the included accessories that come with the Leopold FC660C. There is the expected keyboard cable, detachable but sadly using mini-USB, which in 2021 is an excellent example of what I meant about Leopold operating in the past. The cable is white to match the keyboard itself and has a branded hook-and-loop strap for cable management.
The final set of accessories are two replacement keycaps—one for Control and the other for Caps Lock. If these seem strange to you, it's because the two sizes are swapped from the usual, as these are used when swapping the functionality of the two on the keyboard. More on that later, but we now know that these keycaps are indeed made out of thick PBT plastic (average wall thickness 1.32 mm) with dye-sublimed legends. These aren't the best-quality PBT keycaps I have seen, with residual marks seen on the bottom and sides even. The stem is also clearly compatible with the Topre cylindrical sliders, not the cross-point stems of the MX-style mechanical switches. There is also a cutout for an indicator LED in the larger Control keycap here, with an acrylic piece forced in place that doesn't look great but works well enough.
While not really part of the keyboard itself, I suspect many end users of the Leopold FC660C will be interested in expanding its functionality with an open-source TMK firmware compatible controller. The Hasu controller for the FC660C replaces the stock control board and has the micro-USB port to work with the cable itself, in addition to an Atmel ATMEGA32U4 8-bit AVR RISC-based USB microcontroller with 32 KB flash memory, 2.5 KB SRAM, and 1 KB EEPROM. There is also a button to initiate firmware flashing for the controller, as well as the same ribbon connector as on the default control board, no doubt. For those interested, the Hasu control board for the FC660C costs ~$50 from various vendors.