R1E1T1R1O1R1E1F4L1E1C3T1O1R1
19 points
RETROREFLECTOR is validvalid
a device used for retroreflection [n RETROREFLECTORS]
a device that reflects radiation so that the paths of the reflected rays are parallel to those of the incident rays [n -S]
a device used for retroreflection [n RETROREFLECTORS]
a device that reflects radiation so that the paths of the reflected rays are parallel to those of the incident rays [n -S]