The Parabola Saw reduces manhole cutting time to five to seven minutes by using a spherical cutting blade. This blade prevents misalignment and improves cutting speed, while reducing vibration during cutting. With its circular cutting ability, cross cutting is eliminated. The spherical cutting blade and adjustable arms allow the cutter to be set to 47- or 59-in. diameters, up to 6 in. deep. MK Diamond Products Inc. 800-421-5830