Hybrid Racing K-Series Fuel Rail & Fittings (01-05 Honda Civic Si & 02-06 Acura RSX)Hybrid Racing fuel rails are made from 6061 aluminum with T6 heat treatment and features a durable anodized finish with a laser etched logo ensuring that your engine bay looks fresh and your engine stays fed! Each rail includes a 1 8" NPT hole that allow you to mount a fuel pressure gauge directly to your fuel rail. This puts the fuel pressure gauge in a spot that's easily visible, so you don't have to poke around in the engine bay just to see if you