Honeywell 3/4″ direct ignition dual automatic combination valve

Honeywell 3/4″ direct ignition dual automatic combination valve, 24vac, single stage, step opening, 3.5″wc full rate .9″wc step setting regulator setting, straight through body pattern, 30000-415000btu, 1/2# pressure rating, 1/8″ pressure tapping with plug, ffor use with hot surface, direct spark systems or gas fired appliances