McDonnell & Miller model number 67G is a float-operated low water cut-off with quick hook-up fittings for steam or hot water boilers. This control features an automatic reset with dual switches with millivolt service for low water cut-off and alarm or electric water feeders. Its maximum pressure is 20 psi. Quick hook-up fittings allow for installation directly into gauge glass tappings (1/2" NPT). Blow down valve included.