ICU Medical manufactures medical devices used in oncology, vascular therapy and critical care. These include IV systems, needlefree IV connectors, catheters and cardiac-monitoring systems. The Pfizer unit is ICU Medical’s largest customer. Pfizer acquired Hospira Infusion Systems, which makes IV pumps, solutions and devices, as part of its $16 billion deal to buy drugmaker Hospira Inc. [Resgistration required.]