The online community of knife collectors, A Knife Family Forged in Steel
Sheffield Mfg is an American tool manufacturer.
They make the pictured knife in both a 4" & 5" version.
Great Neck is one of their brands you might recognize.
I've a small multi-tool of their manufacture .. it's a well put together little knife .. decent steel.
The "country of origin" is listed as CHN.
I'm guessing .. that's China.
What you've pictured is a basic Buck 110 clone.
Arguably .. the most copied knife in existence.
sometimes the irony has got to make you laugh
Sheffield = an american tool company
an american tool company = country of origin China
If your in a pawn shop, looking at a used knife as a user. Consider what your going to pay for it, does it name the steel? Is the lockup tight? If it is going to be a user and you know all that upfront, you may just be onto a good user at a reasonable price