[Code of Federal Regulations] [Title 16, Volume 2] [Revised as of January 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 16CFR1203.9] [Page 219] TITLE 16--COMMERCIAL PRACTICES CHAPTER II--CONSUMER PRODUCT SAFETY COMMISSION PART 1203--SAFETY STANDARD FOR BICYCLE HELMETS--Table of Contents Subpart A--The Standard Sec. 1203.9 Test headforms. The headforms used for testing shall be selected from sizes A, E, J, M, and O, as defined by DRAFT ISO/DIS 6220-1983, in accordance with Sec. 1203.10. Headforms used for impact testing shall be rigid and be constructed of low-resonance K-1A magnesium alloy.