Biomotion (i.e. moving lights suggesting that the wearer is a human) is arguably best to promote early detection.

Several arm/ankle models available, mostly for joggers. My use case is extended bike touring. I am looking for:

• something durable, reliable and waterproof
• running on CR2032 (batteries can be swapped in the middle of the night if needed)
• comfortable to wear around the ankle

Comments, tips and suggestions appreciated.