Now you can safely and smoothly ramp over those raised manholes or manhole risers during road construction projects in a matter of seconds using the Manhole Safety Ramp. Made of tough, durable rubber, these Safety Ramp Rings fit securely around raised utilities or manhole risers. They won't shift or slip. Just drop them in place, and remove then simply by picking them up. You'll increase safety and save money by reusing them again and again, year after year.