Air is infused with the water at the pump impeller

50643-1000 - Size 3/4"

positive-lock action slide and swivel design

They have overload

Color White Diameter 3/4" Inlet

Ultra Safety Systems - Ultra Pump Switches, Junior Part No. UPS-02 12V Speakers Air is infused with theAlarm Ready H x Dia Volts No 6 1 4" x 2 1 2" 12 These normally open pump switches operate by a magnetic reed control switch. They are self cleaning with a clog proof design. No timer delays, no electronics or mercury. They are impervious to all materials commonly found in bilges. Switch components are completely sealed against moisture. UPS 01 & UPS 02 are the same except UPS 01 series is alarm ready with an attached sensor for use with A201R optional