The Model QRNG 5120 natural gas compressor is an aircooled, two stage, four cylinder, pressure lubricated compressor capable of handling inlet pressures of -7.5 PSIG (15 in. mercury) up to 15 PSIG. A maximum of 325 PSIG discharge pressure can be produced (with proper controls and modifications). It has a 6" low pressure bore, a 3.25" high pressure bore x 4" stroke and can be run at 400-900 RPM.