1SE1, Honeywell environmentally sealed basic switch, Single Pole Double Throw (SPDT) Circuitry, rated at 5 A at 250 VAC, Pin Plunger Actuator. Honeywell 1SE1 had lead wire termination.
SE Series Environmentally Sealed Basic Switch, Single Pole Double Throw Circuitry, 5 A at 250 Vac, Pin Plunger Actuator, Leadwire Termination MICRO SWITCH™ SE Series and XE Series environment-sealed enclosed basic switches within a corrosion-resistant aluminum housing to seal precision switch contacts from contamination. SE Series switches include an SM basic switch; XE Series switches include the smaller SX Series basic switch.