These are made for the Chrysler, Mopar, Dodge TorqueFlite 727 transmission. It goes in the bell housing (see pictures) and is the vent cover that many people lose when people take their transmissions in and out for rebuilds or whatever. Then some think they don't need them and experience transmission leaks due to the siphoning effect caused by the fast moving torque converter spinning across this vent. This Vent cover minimizes that effect! This design has been mounted/fitted on a Torqueflite 727 transmission and fits great. It is sturdy and is laser cut from stainless steel in Missouri!