MEDO pumps feature a unique, patent-awarded linear-motor-driven free piston system that is globally proven in the wastewater treatment and aquaculture industries. This unique design theory eliminates the wear components typically found in conventional air compressors and vacuum pumps, such as crank shafts, connecting rods and ball bearings. The only moving part is the piston! Also eliminated is the need for any lubrication. Fewer parts translate into fewer problems. A silicone diode between the coils converts the alternating current sine wave into a half-rectified input. The result is a pulsating electro-magnetic field energizing the resonant spring-mass (piston). When the electro-magnet is energized, the intake stroke of the piston compresses the return spring and draws air into the cylinder through the inlet valve in the head of the piston. When the electro-magnet is de-energized, the spring releases and the compression stroke of the piston forces the compressed air out of the cylinder through the reed style outlet valve. SPECIFICATIONS Model LA-120. Power Supply AC 120V. Rated Frequency 60Hz. Operating Pressure Range 1.42 - 3.56 psig. Rated Pressure 0.11 kgf/cm2(2.56 psig). Rated Airflow* 120 LPM (4.24 cfm) or over. Power Consumption 118 W @ 60 Hz. Running Current 2.4 amps. Operating Noise 48 dB Max. Weight 9.4 kg (20.7)lbs. *When operated at the rated pressure noted above