SANDIA aerospace's SA 15 converts Logic Highs to Logic Lows and Logic Lows to Logic Highs, allowing avionics engineers to use common annunciator drive power. The SA 15 uses two darlington arrays that allow up to 14 logic signals to be inverted (seven per array). Input logic levels can be either 28 VDC or 5 VDC or any combination of the two. Two ground inputs are provided (one per array) for annunciator testing. The SA15 can be mounted in the SRU-1 single card enclosure or in either the SRU-5 or SRU-10 multi-card enclosures.

SANDIA aerospace maintains a complete inventory of Line Replaceable Units for immediate delivery should a replacement unit ever be required.