The AllPoints Foodservice Parts & Supplies 321890 is a high-quality pre-filter housing O-ring designed for optimal performance in water filtration systems. With an outer diameter of 4-1/8 inches and an inner diameter of 3-7/8 inches, this O-ring ensures a secure and leak-free seal, enhancing the efficiency of your filtration setup. Crafted from durable materials, it provides reliable longevity and resistance to wear, making it an essential component for maintaining clean and safe water in foodservice applications.