The BD FACSPresto Near-Patient CD4 Counter Book Instructions is a compact and portable device that counters CD4 cells in a sample of blood. This device provides accurate and fast results, making it ideal for medical professionals in healthcare settings. With the included book instructions, users can easily operate the BD FACSPresto and interpret the results to monitor a patient's CD4 cell count. This product is a valuable tool for healthcare workers looking to efficiently and effectively manage patient care.