SCP-003 consists of two related components of separate origin, referred to as SCP-003-1 and SCP-003-2.

SCP-003-1 appears to be composed of chitin, hair, and nails of unknown biology, arranged in a configuration similar to that of a computer motherboard. Testing reveals SCP-003-1 to predate earliest known circuit boards by a factor of thousands of years. SCP-003-1 is considered sentient but not actively dangerous except under certain conditions.

SCP-003-1 was found on a stone tablet, SCP-003-2, on which it currently resides. The runes on SCP-003-2 are not part of any known language, and emit pale, flickering light patterns.

SCP-003-2 is controlled by a (non-biological) internal computer, the contents of which are mostly inaccessible without risk of damaging SCP-003-2. SCP-003-2 is capable of controlled emissions of radiation, including heat, light, and anomalous radiation types. SCP-003-2 contains an internal power source of an anomalous nature, which appears to have been losing power since several centuries before discovery.

It is considered probable that SCP-003-2 was created for the purpose of containing SCP-003-1. Partially interpreted data recovered from SCP-003-2 may refer to a past and/or potential future LK-class restructuring event caused by SCP-003-1.