The 219-3MST is a surface-mount DIP switch featuring a positive detent separate from the contactor and redundant, wiping gold-plated beryllium copper contacts for enhanced reliability. It offers multiple actuator heights (low profile, medium, and extended) with both gull-wing and "J" lead terminal configurations, supporting 2 to 12 switch positions with SPST functionality. The switch delivers a contact resistance of 25 milliohms maximum initially and 50 milliohms at end of life, with an insulation resistance of 1,000 megohms minimum and dielectric strength of 500 VDC. Rated for 2,000 switching cycles at 100 mA @ 20 VDC or 0.1 mA @ 5 VDC (dry circuit), the device meets MIL-STD-202F vibration and shock requirements with coplanarity of 0.10 mm and allowable solder time up to 60 seconds at 260°C. This design is ideal for industrial control, telecommunications, and consumer electronics applications requiring reliable, compact switching with superior environmental protection and RoHS compliance.