In 1981 I purchased my first flashing rear light. The lens was yellow and it was powered by a 9 volt battery. The diameter was about 4 inches and the height was about the same or a touch more. It was held onto a backpack or a seat pack by a large metal clip. For its time I remembered thinking it was neat, high tech and small. Of course in recent years they make things that are 2 inches by 1/2 inch and flash in multiple patterns and are red like car tail lights. They are powered by N batteries or AAA, and they can be seen for a quarter mile or more. They are absolutely brilliant, and they are even now manufactured for bar-end placement, if one prefers. Was there anything smaller or more brilliant back in the early 80's that I'm not aware of?
Garth Libre in Miami Fl.