2 POSITION, 4 WAY AIR VALVE New MAC model 180001-112-0124 pneumatic directional control valve. Two position, four way valve with five ports for use with double-acting air cylinder. Furnished with roller bearing on arm for use as a limit switch or can be manually operated. The arm has three positions and is spring loaded to the center position. Moving the arm either forward or back will actuate the cylinder. When the arm is in the center position, the cylinder will return to it''s original position.