Keysight (Agilent) 34411A
It is 10 years old but was never used. I had a peak inside and there isn't a spec of dust, the fan is also spotless.
Somewhere I'd gotten the impression that when HP removed the fan in later serial numbers of the 3456A, this was because they'd learned that it was best to not have a fan in a precision voltmeter, but I guess 15 years later they'd forgotten that.
Not really picking on this one in particular, just that I've been noticing that a lot of 5.5-7.5 digit multimeters of the past 15 years DO have fans, and that seemed dumb. (Drafts near temperature sensitive parts, leaving dust particles on the sensitive analog board, etc.)
(Though I guess the 3458A has a fan, so I dunno what to think of that. And I am a newbie in understanding the design of high resolution multimeters)