One New Aftermarket Inline Receiver Drier, w/ Female Switch PortFits Case Models: 521E (Has a Place For The Pressure Switch On The Drier), 621E (Has a Place For The Pressure Switch On The Drier), 721E (Has a Place For The Pressure Switch On The Drier), 821E (Has a Place For The Pressure Switch On The Drier), 921E (Has a Place For The Pressure Switch On The Drier)Tech Info: ~ Drier Type: Female / Male O-Ring ~ Inlet Fitting#6 (3/8" Male O-Ring) ~ Length: 10-1/4" ~ OD3" ~ Outlet Fitting#6 (3/8" Female O-Ring) ~ Quality: Aftermarket ~ Service Valve: Side ~ Sight Glass: Side ~ Sold As: Each ~ Switch/Service Port: Female (1/4")Replaces Part Numbers: 9972064, 3713757, 5192346, 9971632, ER047681, 85804063, 9968420, 72278168, 72277664, 76047001, 3688520M91, 0.010.2261.0, 4071007 All OEM part numbers and logos are to be used for identification purposes only