Includes: 40 Devices,1 package insert & 40 droppers - A blood test that measures Hepatitis B Surface Antigen levels - Hepatitis B Surface Antigen is the earliest indicator of the presence of a Hepatitis B infection - The HBsAg test is often used in STD screening as well as health screening for employment reasons - Typically, a negative HBsAg means that the person does not have Hepatitis B. There are rare windows of time in which the HBsAg antibodies will have disappeared while long-term IgG antibodies have not yet appeared.