 SCP-620 is an analog clock of unknown makin' model. It bears no markings indicating a manufacturer or place of origin. Its face is styled after the yellow smiley face design. When SCP-620 is powered, all subjects observing its face experience perceived time acceleration. Constant observation is not required. Occasional glances will induce the perceived acceleration as quickly as constant observation. Upon the conclusion of a testing session, test subjects were asked to gauge how much time they thought they had spent testing. All under-reported time spent testing by a factor proportional to time spent exposed to SCP-620.