The 100SP3T1B1M2REH is a three-position rotary switch featuring a single-pole double-throw (SPDT) circuit configuration with gold-plated contacts. The switch operates across three positions: Position 1 connects terminals 2-3 (ON), Position 2 opens all connections (OFF), and Position 3 connects terminals 2-1 (ON), providing flexible switching functionality. It is rated for a maximum of 0.4 volt-amperes at 20V (AC or DC) with an insulation resistance of 1,000 megaohm minimum and dielectric strength of 1,000 V RMS at sea level. The switch is designed for panel mounting with a 1/4-40 UNS-2A threaded shaft (Ø2.92 mm), operates reliably over a temperature range of -40°C to +85°C, and is rated for 6,000 make-and-break cycles at full load. This rotary switch is ideal for applications requiring compact, reliable switching in control panels, instrumentation, and industrial equipment where space is limited and durability is essential.