The retro reflector reflects the light back into direction of the light source.
Retro reflectors provide safety only as they are of certain optical quality, which means that they can be seen at certain minimum distance (140 m according to the studies in Scandinavia).
The measurement of quality: CE-standard for "High-visibility accessories for non-professional use", which states the minimum requirements for pedestrian reflectors, for reflecting values, water tightness, markings, etc. The standard requires an extensive testing series, according to which the reflector is tested and after these tests, it still has to obtain the min. requirement of reflecting value, which is 400 C.I.L.. Only CE-certified reflectors can be qualified as reflectors or safety items.
