Nitrile 5 Pack Cock Rings 1.75 inches. Nitrile is the same material used to make gloves for emergency room doctors and nurses. Why Nitrile? Because Nitrile is 100% skin-safe and hypo-allergenic. Nitrile is also compatible and safe to use with all types of lubricants. Nitrile is stronger and holds its shape better than latex or rubber it stretches slightly to achieve maximum constriction without sacrificing comfort. Nitrile is available in a wide variety of colors, sizes and thicknesses. If you are looking for an inexpensive and versatile cock ring nitrile is the perfect choice.