The 8-1617807-4 is a hermetically sealed, single-pole double-throw (SPDT) relay from the FCA-125 series, designed for high-current switching. It features a polarized, single-side stable design that uses a permanent magnet to increase contact pressure, ensuring reliable operation. The relay is equipped with a 28 VDC coil with back EMF suppression and silver cadmium oxide contacts with gold plating, rated to switch 25 amps for resistive loads. It operates over a wide temperature range of -70°C to +125°C and is qualified to military standards M6106/19 and M83536/36. This all-welded, balanced-force construction provides high reliability in harsh environments, making it suitable for aerospace and defense power distribution applications.