I used to have one of these about 50 years ago. They were originally metal bodied (later plastic) and pushed on to a metal bracket on one side of the front fork or on a similar bracket on the handlebar stem. They were much more durable than modern lights.
Last week I hit a slight bump in the road and the Halfords Bikehut front light jumped out of its mounting and smashed in to 6 pieces. It cost about £35 and hadn't been used much. Got in touch with Halfords to be informed they don't supply replacement clear lens. Really annoyed
I am now using Cateye lights which seem to be of better quality and a bit stronger.