The RPHA 10 is the top end race spec lid worn by riders like Jorge Lorenzo. However, its USP is that it offers top level kit for a lot less than its rivals. My lid is a USA spec one that conforms to DOT standards and is pleasantly light but pick up a Euro spec one and you will be shocked at how little it weighs.
The shell is constructed with a combination of fibreglass, carbon fibre and Aramids. It is quite compact, a little narrow at the base and generally oval in shape. A double D ring retention system keeps it firmly fastened. HJC has three different shell sizes as you go through the sizing chart. The graphic here is the Buzzsaw that also comes in Black/White and Black/Red. It looks extremely aggressive and seems of high quality but look closely enough and you will notice some tiny dust spots.
Extensive wind tunnel testing was done in the development of its shape and ventilation. I find that the helmet is silent enough that you don't need to use ear plugs in traffic, although I still prefer to. Ventilation is good enough that I don't need to open the lockable visor (a small clasp at the front holds it down for high speed use) when at traffic stops. Being a race helmet, it vents best at a slight downward tilt where air gets drawn through the adjustable top vents, over the head and pulled out through the rear venturi exhausts built into the spoiler.
The fit is snug but comfy with fully removeable and washable interiors that are made in a plush feeling moisture wicking material that is also anti bacterial. I opted for an extra smoke visor that also works with HJC's anti fog Pinlock system. However I have found that you can use the helmet without the anti-for Pinlock insert and it works just fine in Mumbai's heat. The RPHA 10 costs Rs 30,000 (Rs 23,000 in USA for this graphic scheme) in India and while that may seem expensive, it's actually excellent value compared to what the admittedly slightly higher spec competitors from Japan would set you back by.