helmetn.头盔；安全帽helmet-mounted binoculars头盔式双目望远镜Helmet of Black Knight Chief黑骑士队长头盔Helmet Mounted Cueing System头盔提示系统Helmet Position Sensing System头盔位置感觉系统helmeted radio speaker-phone盔式无线对讲机Helmet Optical Position Sensor头盔光学位置检测器helmet-type diving apparatus头盔式潜水装具Helmets for motor vehicle users摩托车乘员头盔Helmet Attitude Tracking System飞行帽式姿态跟踪系统helmet-mounted display system头盔显示系统