... Series)* 3A110, 3A120(N. O. ), 3A120(N. C. ), series air operated valve. * Exterior control, 3 port 2 position. * Port size: M5&chi ... /8".* 3A210, 3A220(N. O. ), 3A220(N. C. ), series air operated valve. * Exterior control, 3 port 2 position. * Port size: 1/8 ... /4".* 3A310, 3A320(N. O. ), 3A320(N. C. ), series air operated valve. * Exterior control, 3 port 2 position. * Port size: 1/4 ...