Honeywell 3/4″ 24vac standing pilot dual automatic combination valve

Honeywell 3/4″ 24vac standing pilot dual automatic combination valve, straight flange x npt, 3.5″ water column, step opening, single stage, straight through with flange, 30000 btu to 290000 btu max, 1/2# pressure rating, 1/8″ npt pressure tap with plug, includes 3/4×1/2″reducer bushings (20