2 years ago, I changed the brand of helmets I wear to Bell from Arai, which I had been wearing for 20 years. I did it because Bell, has exclusive licensing for "Transitions" technology for their face shields. Just like "Transitions" sunglasses, they go from clear with no sunlight all the way to dark, with full sunlight and anything in between depending on the light conditions. I've been really happy with the helmets ever since. I bought just an inexpensive one, ($109) first and then upgraded to a $400 helmet after 6 months. The "transitions" shield is the same for every helmet they make, even for the Carbon Fiber racing helmets.
Yesterday, Bell Helmets came to the Honda/Kawasaki motorcycle store I work at and brought their equipment for their "Custom Sizing Program". They used a lazer system to create a 3D map of my head.
The information is then sent in to Bell so they can build a helmet specifically to fit me. There will be a huge difference in comfort and an even bigger difference in the safety. Inside of motorcycle helmets have a styrofoam liner that serves as the deceleration zone that actually cushions your head and crushes during impact to minimize your brain slapping around inside your noggin. On top of that is the normal comfort area that you actually feel.
With the custom sizing program there is very little comfort foam and twice as much of the "deceleration" styrofoam. This foam is not solid but is in channels that allow it more room to compress, making it "cushier" for your brain and also serves as deeper channels to allow the airflow system more room to work.
There has never been any type of custom system ever and I think it is going to be a huge deal. I also choose, depending on my riding position, how far up or down I want the eye hole, within limitations. Mine will be 3'$ inch higher than standard because I am a sportbike rider and am in a "tuck" position unless sitting at a light.
These are pricey, but no more so than a top of the line Arai which has no custom sizing. It also take about 4 weeks to build and ship each helmet. There are no colors available, just natural carbon fiber weave. Bell also has this available for their carbon fiber motocross helmets.
I'll let you know how it actually feels when it comes in. I plan on wearing it for about a month before sending it out for custom painting.