The Evolution was the first ultra sick MTB helmet by GIRO back in the late 90's for $130. The E2 replaced the Evolution. Then they started doing the XEN series and the E2 was replaced by the super Euro looking XC lid the Athlon. The XAR is if the E2 and the XEN had a baby, but better cuz the ROC LOK 5 is the best ever. Giro took a page from Bell's book with this one! @$64 I got mine for bro-deal pricing! STOKED. Chainlove and Hucknroll kicks ass!