Automatic bilge pump operation (1 1/4" differential) with isolated high water alarm switch (at 3"), built-in. Specify 12V at 15Amp U.L. or 24/32V at 10Amps U.L.(30 Amps relay). Alarm circuit is Normally Open or Normally Closed contacts (current limited to 100 mA max). Specify N.O. or N.C. Lifetime warranty.