Apollo Lunar Module Separation Sequence Controller, designed by Autionetics to be mounted in the Saturn V Spacecraft Lunar Module Adapter (SLA). Part of the Sequential Control Event System (SECS), the controller was responsible for triggering the squibs (explosive charges) that allowed the Lunar Module to be extracted (by the Command Service Module) after launch. The controller measures 11" x 4" x 9" and is mounted on a pair of 14.5" long fiberglass rails. The unit is covered in thermal foil tape, with no part numbers apparent.
