Naprec - Intake,Exhaust Valves Guides Set - Honda - B18C Standard typeSpecifications: Manufacturer: Naprec Reference Number: NAP VG HB18 Naprec is simply the best Engine Machinist in Japan, With thousand years of experience, they supply the biggest tuning shop in Japan. The valve guide was a thing where the inner diameter part was bent when press fitted and replaced. Our valve guide is manufactured in a shape that causes almost no bending due to our own know how, so it can be used with almost no inner diameter