confidential cpus are typically engineering samples, usually given to motherboard companies to work on bioses for the cpu generation and meant to be returned to the company after done. engeering sample cpus can be missing features, lower clocks and such that the retail varient may have.
as for geneeation of cpu, its easier to find out via what motherboard socket it is
on thecontext of finding second hand, i wouldnt say its common, but can happen. some chinese companies sell dirt cheap ES cpus for basic computing.
the ilm says lga 115x, so its either 1156(1st gen), 1155(2nd or 3rd gen), 1150(4th and 5th gen) or 1151(6th to 8th gen)
if you have a garage, design a method to basically ensure your garage door is closed without you needing to go back to check.
of course if you trust yourself with never making that mistake.
last thing you want to feel is if you remembered to close the door or not and youre already far off