We're talking about SCP-5000 Absolute Exclusion Harness right? That's the main famous SCP where the foundation starts trying to exterminate humanity. But yeah, it's all told through digital archives onboard a wearable device that renders the wearer completely safe from basically reality as a whole that just appeared and tells of a chilling alternate reality where the foundation starts exterminating mankind and it is implied that the wearer ends up using the suit to survive and then "reset reality" using some other SCPs and that reset reality where that all never happened is the reality the rest of the SCP Foundation we know exists. The Harness is the only thing left as it is shielded fully from basically anything.