This specification covers the minimum safety and performance standards that a manufacturer should meet with regards to the design, manufacture, testing, labeling, and documentation of cranial traction tongs and halo external spinal immobilization devices intended for use on humans for therapeutic purposes. It is, however, not to be construed as production methods, quality control techniques, manufacturer's lot criteria, or clinical recommendations for such. Requirements to which the devices shall be tested on and conform accordingly to are magnetic resonance imaging (MRI) compatibility, mechanical integrity, design performance, induced current flow, and current induced heating.