Dual-camera helmet gives cyclists eyes in the back of their heads
Helmet Bike Mirror, Stylish Long Bike Rear View Mirror Velcro Flat Mirror Universal Bike Accessory for Mountain Bicycle/Cycling/Scooter/Kid's Bike/Moped (Black) : Amazon.co.uk: Sports & Outdoors
6 Best Bike Helmet Mirrors 2017 - YouTube
Sneak peek: Bell launch new commuting helmets | road.cc