Features: Iso-Valve™ � Isolates the pump from the system with just a quarter-turn. Gas Ballast � Moisture laden air passing through the pump mixes with relatively dry air to such a degree that compression does not cause condensation. Two-stage Design � Cleans the system more thoroughly than a single-stage pump; the second stage starts pumping at a lower pressure so you can pull a deeper, ultimate vacuum. Oil Drain Valve � Positioned at the bottom of the oil reservoir and angled for faster, more complete draining. Oil Fill Port � Makes adding oil simple since the port is accessible from the front or either side. The sight glass on the front of the pump shows you when enough oil has been added. Offset Rotary Vanes � Our proven design builds a powerful compression within the pumping chamber to reduce system pressure and vaporize moisture so it can be exhausted along with air. Molded Base � Durable polycarbonate base improves pump balance and minimizes vibration during operation. Die-Cast Aluminum Housing � Cast aluminum housings make the pumps lightweight but durable. No. 15601 � 142 L/M, 20 microns, 2-stage, intake fittings 1/4" MFL and 1/2" MFL, oil capacity 15 oz. (445 ml), 115V/220-250V 50/60 Hz, 1/3 hp motor.