Yeh, it's a set of ground wires. It looks just like the TC Sportline ground system. http://www.tprmag.com/issue/8/tc.shtml http://www.tcsportline.com/
I think that piece where all the cables come together is just called a 'distribution block.' ionno what purpose it serves or anything.. actually it might just be called a 'circle plate.' makes sense i guess.
"HKS Circular Grounding System - By utilizing a 24 karat gold plated distribution block and multiple grounding points, improved idle and drivability are often obtained as the additional grounding points equalize resistance and voltage between various ground points. Each 8 gauge spiral twined cable is wrapped with signature HKS purple plastic to protect and add color to the Circle Earth System. Vehicle specific kits included pre-measured cable lengths and distribution blocks." http://hksusa.com/products/?id=1506&rsku=0
"Circle Plate - The HKS circle plate allows for the freedom to choose the thickness and the number of wires (up to 24 lines) to be used. Depending on the specific application, either the Separate Type (remotely located from battery terminal) or the Direct Type (directly mounted onto the battery terminal) are utilized.
24K Gold Plating and High Quality Wire - Each of the 8scq wires consist of 658 winded 0.12mm lines that allow each wire to withstand up to a maximum of 65A."
 It's been discussed here before I think. Most people would proly just post up a response like, "Go to home depot and save yourself some money..." Which could proly be true, but if you read the product details for Sun Auto systems or APEXi, etc., they'd advertise 99.9% shielded copper wires. I think copper is one of the most conducive materials, second to silver.
I think it's APEXi that says that their ground system only works on highly modified vehicles.
Larger ground wires give off less resistance or something. The best I can explain is that with smaller wires, more voltage loss is experience when more devices are demanding power from the same electrical source. With a larger guage of wire, there would be less of a voltage loss because of a larger surface to flow the electricity. Most of the things that a larger guage would affect would be things like the starter, alternator, injectors ... or maybe I should say that the only things that wouldnt really be affected would be sensors n stuff, since they don't have as much a demand for electricity as some other components. Perhaps the only effect the sensors might experience would be from a higher magnetic field being generated by the wires. I think that any electical current generates a magnetic field.
um, but anyway. I read about the peformance gains that are supposedly to be had, but that it would only be true if the efi sensor grounds are so bad that the computer was misreading the signals. More energy to the ignition system wouldnt really help either, coz if it's firing it's firing. If not then you're engine isn't running. More energy to the ignition might just be bad news, coz of spark plug wear.