Revision has modernized the traditional advanced combat helmet Viper P4 system is up to 34% lighter than the legacy U.S. Army ACH and represents the first significant advancement in ACH technology in 15 years Advanced composite shell technology combines elite protection, extended-use comfort, and impressive weight reduction Revision has modernized the traditional advanced combat helmet: The Viper P4 system is up to 24% lighter than the legacy U.S. Army ACH and represents the first significant advancement in ACH technology in 15 years. Revision*s advanced UHMWPE helmets meet stringent quality standards and exceed U.S. military specifications for ballistic threats, blunt impact, and blast fragmentation. Advanced composite shell technology combines elite protection, extended-use comfort, and impressive weight reduction.