Brand: AutomationDirect Item: Mechanical interlock For Use With: GH15NT, GH15PT, GH15RT, GH15ST or GH15TT series contactors Application: Mechanically connects contactors to prevents both from being pulled in at the same time AutomationDirect mechanical interlock, for use with GH15NT, GH15PT, GH15RT, GH15ST or GH15TT series contactors, mechanically connects contactors to prevents both from being pulled in at the same time.