You can instantly see when a car slows down due to the bright red brake lights – but the same isn’t true for bikes. That’s why Revolights just launched the Arc – the world’s first integrated brake light for bicycles. The Arc uses Revolights technology to track wheel speed, so it can sense when you’re slowing down and switch on a bright red LED to alert traffic behind you. It also doubles as a fender, it can easily be seen from both sides and behind, and it’s powered by a lithium ion battery that can be recharged by any USB port. Revolights just launched a Kickstarter campaign where you can pick up your own Arc light – check it out here!