The RIDGID 42778 Set of 29 mm and 24 mm Pipe Guides are suitable for use with the SeeSnake nanoReel and can fit a 15.5 mm camera. The ball guides are designed to help center the camera in pipes, keeping the camera clear of bottom sludge in the pipe. By bringing the camera head closer to the center of the pipe, the pipe guides improve picture quality, allowing the camera to see equally in all directions and helping to keep the camera lens clear during inspections.