The Reinz Transmission Cooler Line O-Ring - 407695700 is a replacement o-ring for transmission cooler lines. It is designed to create a tight seal between the cooler line and the transmission, preventing any leaks or fluid loss. This o-ring is made of durable materials to ensure long-lasting performance and is compatible with a variety of vehicle makes and models. It is an essential component for maintaining the proper function of a vehicle's transmission system.