The Air Slave Valve actuates the pneumatic cylinder to control the high and low ratio on the vehicles transmission. Constructed of durable materials, the Air Slave Valve provides a longer service life. Product Features:Prevents the transmission from becoming stuck in a high or low ratioReplacement restores full functionality to the transmissionEasy to install - no special tools necessary for installationThis part has undergone Vehicle Try-on testing to meet product standards and quality