Poly Insert fittings are used with Polyethelene Sprinkler system pipe, which normally is black, and sold in coils of 100' or 300'. Poly pipe is rarely used in Texas, Arizona, New Mexico, California, Florida, but quite common in Michigan, Virginia, New York, North and South Carolina, Minnesota, Michigan, Winsconsin, Washington, Illinois, Nebraska, Iowa, North and South Dakota, Colorado, Utah and other regions.