This retarder valve is compatible with Allison Transmission 23010149. It is a high-quality automatic transmission part that ensures smooth and efficient performance. The valve is designed to regulate the flow of fluid into the transmission system, ensuring that it operates at the desired speed and pressure. This item has been carefully selected to meet your needs. It is a reliable and durable part that will keep your transmission system running smoothly for years to come. It is easy to install and requires no additional modifications to your vehicle. Buy with confidence knowing that you are getting a quality product that will meet your expectations.