Trainers with lights
Most of the shoes which my children wear have flashing lights in them, activated by pressure when they walk and run. Sometimes it’s just a single LED, sometimes they’re dotted all over the shoe, and there’s a miniature Christmas tree effect with every step.
What I’m puzzled by, though, is why this feature is found only in children’s shoes, not in adult’s. It seems like such an obvious and desirable safety feature for anyone who runs outside at night, yet as far as I know, it remains the exclusive preserve of children’s shoes. Strange.