|The BY-500 was the first of many warning signals to be developed. The rotor is manufactured from heavy-duty styrofoam with reflective labels that are visible within a 360-degree radius. The rotor spins atop a shatterproof 5-foot fiberglass rod and can be seen over the rooftops of most oncoming vehicles. A steel bracket attached to the rod mounts on the rear axle of a bicycle. Safe T Spin adds an extra margin of safety when combined with any vehicle's required safety devices.