A controller assembly for delivering pressurized fluid to a compression treatment device includes a first pump assembly including a first pump unit and a first electrical contact. The first pump assembly defines a first pneumatic passage configured for fluid communication with the pump unit. A second pump assembly includes a second pump unit and a second electrical contact. The second pump assembly defines a second pneumatic passage fluidly communicable with the second pump unit. The first pump assembly defines a receptacle into which the second pump assembly is slidingly receivable. The sliding reception of the second pump assembly into the first pump assembly establishes fluid communication between the first and second pneumatic passages and establishes electrical communication between the first and second electrical contacts.