The CAT 3K-0360 2.21X16.36mm 90A NBR O-Ring is a genuine Caterpillar replacement part designed for heavy equipment. This 2-pack of O-rings is compatible with Caterpillar machines, ensuring a precise fit and reliable performance. Made from durable NBR material, these O-rings are designed to withstand high temperatures and pressures, making them an essential component for maintaining the efficiency and longevity of your heavy equipment.