The RPHA-10 helmet from HJC is a higher end, more aggressive style helmet in the RPHA (Revolutionary Performance Helmet Advantage) family of helmets. The RPHA Max is the modular for cruiser or commuting riding, the RPHA-X is the off road version. The previous HJC RPS-10 and now the RPHA 10 helmets were designed for Ben Spies, a MotoGP racer, so the shape and design of the helmet is made for more aggressive riding and track use. The helmet can be used in an upright seated position but functions best in the leaned forward position. I currently have and use the RPS-10 Spies replica helmet and after checking out the RPHA 10 I found the main difference between the two helmets is in the venting. HJC improved the vent on the chin bar, making it a little bigger and easier to operate. The other difference is the HJC logo above the visor has been replaced with the signature “R” for the RPHA series helmets. I would say this helmet is more of an intermediate oval shape and not quite as round as what you will find in most other HJC helmets. Since this is a helmet designed for performance at higher speeds the helmet is very aerodynamic and is made to fit snug around the jaw and the back of the neck. This makes the helmet a little difficult to get on and off at first but once it is on the helmet has a snug but comfortable fit. The shell of the helmet is made from a carbon fiber and fiberglass epoxy. This makes the helmet very durable and extremely light. The RPHA 10 comes in 3 different shell sizes so you can do a little cheek pad changes to adjust the fit. Each size has 2 different cheek pad sizes that will fit in the helmet. The helmet comes with the HJ-20 shield which is Pinlock ready and comes with a Pinlock insert in the box. The interior of the helmet is fully removable for cleaning or replacing. It is made from a super soft moisture wicking fabric that is anti-bacterial. The RPHA 10 also comes with a breath deflector and a chin curtain installed on the helmet. The venting on the chin is split with some flowing up to the shield, keeping moisture from building up on the inside of the shield, and some flowing around the sides of the helmet. There are two more intake vents on the top of the helmet that have a six position closure which makes it very easy to adjust the amount of air flow into the helmet. When you remove the liner from the helmet you can see where the venting continues in the EPS liner that allows the air to flow in from the vents and channel the airflow over the top of the head and out the exhaust vents in the back of the helmet. :: Aaron, 02-23-13