I bought size Large and it weighs 342g which surprised me. I have a Bell Furio which is a low end helmet that ways 322g. I was hoping the Volt would be around 280 (as advertised), noticeably lighter than the Furio on a long ride. Still, everything else about the helmet feels very comfortable and it's about the same weight as the Giro Saros helmet (330g) that I returned (looks huge, and the adjustment mechanism is not as easy as the Volt's wheel).
I really feel the super premium price point of the helmet should be on the light side of the spectrum, hence the three stars.
RealCyclist is awesome in their customer service, excellent return process and cheap return shipping makes ordering risk free.