TCAS II GRAY NVG DISP 1/2 071-01618-0225Primus II Select Control Head | TCASII, Gray Faceplate, NVG Display, DualThe PS 578 is the control unit for use with MST-67A Enhanced Mode S Transponder (-2001/2101 versions) and contains all controls required for transponder operation including TEST, STANDBY,..