All Velocity lacrosse Practice, High School, and Fully Certified lacrosse balls are constructed the same exact way. You can now choose the exact ball that you need for the level of play and requirements your organization needs. NFHS Rules state that a lacrosse ball must be SEI Certified to the NOCSAE standard to be compliant for High School Lacrosse. Some schools might require the NFHS stamp, however this is not the NFHS rule.