Transmission Cooler Thermostat Bypass for 6L80/6L90 Fits Silverado Sierra This transmission cooler thermostat bypass plug is specifically designed to fit into the stock thermal bypass housing on your transmission cooler lines, helping to keep your transmission running cooler and extending its lifespan. Constructed from aircraft-grade aluminum with precision CNC machining, this high-quality bypass plug is built to prevent costly repairs by avoiding thermostat failures. The included Buna O-rings ensure a secure fit and effective sealing. Ideal for GM vehicles equipped with 6L80, 6L90, or 8L90 transmissions, it is recommended to verify compatibility before purchase. When installing, apply transmission fluid to the O-rings for a smoother installation and to prevent potential damage. Brand NEW transmission cooler thermostat bypass for extended transmission life Fits 6L80, 6L90, and 8L90 transmissions, compatible with many Silverado and Sierra models Made from aircraft-grade aluminum with CNC machining for durability and precision Designed to replace stock thermal bypass, reducing overheating and preventing failures Equipped with Buna O-rings, ensuring a secure and leak-proof installation. (description exceeds maximum possible length)