Not knowing what the size actually is, it looks familiar. Given the bootprints on it, it looks like it's a pretty good-sized chunk of aluminum. It reminds me of the back panel of some of the Sun 3/2xx and 4/2xx server chassis. Large, heavy switching power supply and backplane inside. Even when devoid of circuit cards, the chassis was pretty heavy, and by the time you added CPU, memory and I/O interface cards, it'd get even heavier. I figure that the weight on the warning tag is "empty" weight, which seems about right based on my memory. I could be completely wrong, though, as I am not at a place where I can look at the old Sun 4/280 system I have to compare the covers with the photo - and there were lots of machines in the '90's that were physically large and heavy that used similar chassis materials. -Rick -- Rick Bensene The Old Calculator Museum http://oldcalculatormuseum.com -----Original Message----- From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Kyle Owen via cctalk Sent: Friday, March 30, 2018 6:32 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: Identifying an aluminum panel I feel like I should know what this panel goes to...I found it in my garage when cleaning up. Any ideas? http://i.imgur.com/u4LMNqE.jpg Thanks, Kyle