Yup. Short ram.

I'm skeptical of the 15 hp increase. Does that mean 10whp on the dyno? from just replacing the stock filter? And where on the power curve is it? Midrange? (that can't be top-end)

Take it this way... Most 2.0 engines will see a 15whp (20bhp) increase total at the top end from a short ram intake, headers, midpipe and tambutso (hehehe). It's nearly impossible to get that much from just a short ram.

In fact, the complaint of many aftermarket vendors in the US is that new Nissan engines are hard to get power out of. Case in point, the 350Z. This is a shtonking big 3.5 liter V6. Guess how much power you get from an air intake?

C'mon, do the math and guess. If a 140 hp car can get 5 from a short-ram... 3.5% or so... then a 280 hp engine should get 10 hp, right? Wrong. It gets the same 5 hp. Nissan's new engines and their assorted plumbing are pretty good.