The Core i7-8086K Limited Edition is a Coffee Lake-based processor with six physical cores capable of executing 12 threads. It's is the highest-clocked SKU in Intel's mainstream processor family with a base clock of 4GHz and a single-core turbo frequency for 5GHz. For comparison, the current Core i7-8700K has base and single-core turbo frequencies of 3.7GHz and 4.7GHz respectively.
In addition, its "K" designation signifies that this processor is fully unlocked for your overclocking pleasure. We don't see this as being much more than a clock speed bump in the grand scheme of things, so it still has a 95W TDP, 12MB of L3 cache and support for DDR4-2666 memory.
Intel is only making 50,000 of these processors available, so don't expect for them to have the same lengthy lifecycle as its other offerings. However, you do have your chance to win one of 8,086 Core i7-8086K Limited Edition processors that Intel is giving away (2,086 of those processors are earmarked for entries in the United States). The sweepstakes is opening on June 7that 2PM EST and you will have a 24-hour window to make your entry at the following website.
Intel did not give an official price for the Core i7-8086K Limited Edition, but the official rules for the sweepstakes says that the value of processor is $425. That compares to an official MSRP of $359 for the Core i7-8700K.