Tridicator(boiler gauge) 2.5" dial,black steel case, plastic window,1/4"NPT back or bottom. Tridicator:One gauge measures both temperature and pressure.2.5" dial,black steel case, plastic window,brass wetted parts,1/4"NPT back or bottom connectio,dual scalesRange:0-75psi/kPa,60-320F/CAccuracy: pressure ±3-2-3%,temp.±2%***Other ranges or thread size available upon question***