M3786/4-0877 is a multi-deck rotary switch manufactured by Grayhill, designed for reliable switching in demanding military and industrial applications. The switch features a 1-inch diameter with a 1-amp rated capacity and is available in Series 42, 43, 44, and 54 configurations, offering many circuitry options and multiple deck configurations ranging from 1 to 12 decks. It is MIL-qualified to MIL-DTL-3786/4 specifications with options for shaft/panel sealing, adjustable stops, and PC termination, and is UL recognized. The switch operates across temperature ranges of -65°C to 85°C (unsealed styles M, MB, MG, MBG) or -65°C to 125°C (sealed styles H, HB, HG, HBG, HS, HBS, HGS, HBGS), with electrical ratings including 1 amp at 115 Vac resistive for 30° or 36° throw angles, and up to 5 amps at 115 Vac resistive for 45°, 60°, and 90° throw angles. The rugged construction ensures reliable operation throughout the equipment's service life, making it ideal for military equipment, aerospace systems, and other applications requiring dependable multi-position switching with low contact resistance and high dielectric strength.