... Port Air Operated Valve (3A100, 3A200, 3A300 Series)* 3A110, 3A120(N. O. ), 3A120(N. C. ), series air operated valve. * Exterior control, 3 port ... . * Port size: M5χ 0.8, 1/8".* 3A210, 3A220(N. O. ), 3A220(N. C. ), series air operated valve. * Exterior control, 3 port ... 2 position. * Port size: 1/8", 1/4".* 3A310, 3A320(N. O. ), 3A320(N. C. ), series air operated valve. * Exterior control, 3 port ...