397PC O-Ring Assortment Kit Plumbing Paintball Metric Nitrile Rubber Air Gasket Red Hound Auto Deluxe 397-Piece Metric O-Ring Kit Heat, water and oil resistant nitrile rubber construction Ideal for workshop and home applications, including plumbing and hydraulics Kit includes a wide assortment of the most common O-Rings Sizes from 3mm - 50mm Includes handy storage case