Built from Poly-Carbonate, the base material in bullet-proof glass The Surge Series 5 Piece Set from Reese Outdoors is designed to withstand all of the elements you can take it through. It produces all of the sounds needed while in the field working coyotes and other predators. From coyote vocalizations(male, female, and pup) to rabbit and rodent distress, know that years of research, testing, and field testing have gone into this call set.