Looks kinda small and not nearly as much suface area as the K&N cone filters that come with the Stillen and JWT.
The reason for this is because it's a foam type filter and not a paper type filter. HKS only uses this foam element. I had one on my previous car and it works good.
Just make sure it's oiled because that's how it traps dirt and dust!
Looks cool, all you need is a heat shield now! That area gets pretty hot when the car is not moving. I know cos my JWT heatshield is hot to touch when i leave the car running but not moving.
8)