This user's manual covers the Hybrid III 3-year old child test dummy. The manual is intended for use by technicians who work with this test device. It covers the construction and clothing, assembly and disassembly, available instrumentation, external dimensions and segment masses, as well as certification and inspection test procedures. It includes guidelines for handling accelerometers, guidelines for flesh repair, and joint adjustment procedures. Finally, it includes drawings for some of the test equipment that is unique to this dummy.