Leak proof all welded heavy duty carbon steel bodies coupled with snap action or mercury switches provide reliable, long term service for compatible liquids. The use of an external magnet reduces the possibility of magnetic particle build-up inside the armature tube and subsequent loss of operation as may occur with the internal magnet repulsion design. A variety of snap action or mercury switches in SPST, SPDT, DPDT or DPST configurations will satisfy most electrical requirements. These switch assemblies are contained in NEMA-1 general purpose, NEMA-4X weatherproof, NEMA-7- 9 groups B, C, D, E, F, G, explosion-proof or explosion-proof – vapor proof enclosures.