Weil McLain 510 218 100 Gauge Els PW 17895 Always verify your specific model's Always verify your specific model's gas type and manifold pressure requirements before installation The White Rodgers F29 0225 is a heavy duty clear plastic thermostat guard engineered to prevent unauthorized tampering and physical damage in high traffic environments like schools providing technicians with clear visibility for precise diagnostics on commercial and residential boiler systems this specific combination pressure vacuum gauge is optimized for steam systems where monitoring the vacuum during the cooling cycle is necessary for proper air venting and operation