Over-center actuator block and plunger design gives crisp actuation, diminishes sparking, and increases operating life. Bright, LED illumination at top of actuator (for illuminated models). Anti-jamming design protects contacts from damage caused by excessive downward force on the actuator. High internal barriers between poles, and insulating sheet between case and actuator block, give added protection to contacts. Specially composed silver alloy contacts for power applications, or gold contacts for logic-level applications, give high contact reliability. Prominent external insulating barriers increase insulation resistance and dielectric strength. Epoxy-sealed terminals prevent entry of flux, solvents, and other contaminants. Clinching frame to case well above base and terminals provides 1500V dielectric strength. All models are certified by CSA and recognized by UL.