Stabila. With most homes having at least two vents through the roof, the Vent to Roof V2R Laser offers a solution for more easily and accurately locating vent pipe roof penetrations. Simply place the self-centering tool in any pipe or hole ranging from 11/2 inches to 41/4 inches in diameter, and the laser will identify the appropriate venting location. Ideal for venting plumbing fixtures, combination vents, radon gas vents, and more. 800.869.7460.