Both units of the JustSling look identical in terms of design. PowerColor has placed a little sticker on each, so that one may employ these properly. The entire unit and the stands are covered in a soft surface material, similar to the "SofTouch" or "Leather Touch" coating used on cases from BitFenix and Xigmatek. Placing the units unto the stands is easy enough, but I would have liked to see some sort of clipping mechanism, so that they hold in place properly. As it is now, they both have some play when standing on these bases. For the comparison of the two units, I have placed the transmitting unit on the left and the receiving unit on the right. The following images retain this placement.
Taking a look at the front, there is a noticeable difference in the placement of the plugs. While the green LEDs are at the same location, the mini-USB connector and reset buttons differ. In the rear, a similar difference presents itself, but you also get a plug to connect the included IR Blaster to the transmitter unit. There are air vents on the top and bottom of the devices. PowerColor has placed a warranty seal on one of the screws, as there is absolutely no reason to open these up, but we will do so anyways.
Transmitter
Taking things apart is quite easy after removing the two screws. Just pop off the cover, which allows you to unscrew the PCB from its base and pull it out of the casing. Please excuse the fact, that the picture turned out to be upside down.
About half the unit consists of an antenna array. Five antennas converge to the center and ensure that the data is transported properly to the receiving unit. Interestingly enough four of these also feature a tiny plug to which one could connect more antennas theoretically.
There are several ICs on the very clean PCB. The Amimon AMN2120 WHDI Baseband & AMN3110 RFIC Transmitter chips are at the heart of the magic, as these are responsible for the WHDI standard. The Amimon Website summarizes the features nicely:
Designed for the WHDI standard
HD video: 1080p/60Hz & high quality computer graphics; equivalent video rates up to 3Gbps
Range: house coverage, through walls.
Latency: less than 1 millisecond
Hollywood approved HDCP 2.0 copy protection
Low power consumption modes for portable devices
Low cost – mass adoption price points
5 GHz unlicensed band with support for Dynamic Frequency Selection (DFS)
Then, there is the STMicroelectronics STM32F105RB Connectivity line, ARM-based 32-bit MCU with 64/256 KB Flash with an ARM Cortex-M3 32-bit RISC core running at 72 MHz. The the side of this one is also a tiny button, which is not reachable from the exterior of the unit. Last, but not least there is the ITE IT6605E which seems to be used to implement the HDMI input. Interestingly enough, neither the ITE site or the PowerColor specifications table mention which version of HDMI this IC is capable of. Since the unit is supposed to be able to transmit 3D over WHDI, I assume HDMI 1.4 may not be impossible.
Receiver
The receiver is opened up in the same manner as the transmitting unit, but the PCB varies quite a bit.
The antenna array has a slightly different shape, but also features a total of five antennas. A foam spacer has been placed on the center. Oddly enough, the transmitting unit does not feature any such padding, while the receiver has a few.
The above IC is the main reason why the two units are not interchangeable. As you have a transmitting Amimon chip in the other unit, the receiver holds the AMN2220 WHDI Baseband & AMN3210 RFIC Receiver chips.
You will find the exact same ARM Cortex based IC here as well - next to a mysterious button once more, but theITE IT6613E chip is much more revealing and manages to answer the one question which is of vital importance. In the depths of the Internet I managed to find the following sentence:
The IT6613 is a high-performance HDMI transmitter, fully compatible with HDMI 1.3, compatible with HDMI 1.4a 3D and HDCP 1.4 compliance and also backward compatible to DVI 1.0 specifications.