The RADIUM Dual Catch Can Kit for 2010+ Evo X consists of the PCV Catch Can Kit and the Crankcase Catch Can Kit:

The PCV Catch Can Kit is compatible with all 2008-up EVO X models. It installs immediately behind the RH headlight and plumbs in-line with the PCV hose. When the intake manifold pressure is close to or greater than atmospheric pressure, the PCV "check" valve closes and, thus, this hose experiences no flow. Conversely, the PCV hose will experience "metered" vacuum when the engine is idling, steady state cruising, and decelerating. This would normally draw unwanted crankcase vapor, unspent fuel, and oil sludge into the intake manifold immediately after a high load run. Note: Because Radium catch cans are pressure sealed, they are great for boosted applications as well so connecting to the intake manifold is permitted and will withstand any boost level.

The Crankcase Catch Can Kit install immediately behind the LH headlight and plumbs in-line with the crankcase vent hose. This is the hose that connects from the port on the valve cover to the turbo air intake pipe. On 2008-2009 EVO X models which use the "metal" valve cover, the hose is 3/8" (10mm) and requires P/N 20-0106-08. On 2010+ EVO X models which use the "plastic" valve cover, the hose is 1/2" (13mm) and requires P/N 20-0106-10. During low engine loads, this hose experiences atmospheric pressure, but when the engine is at high load (WOT), this hose will experience vacuum and would normally be drawing unwanted crankcase vapors, unspent fuel, and oil sludge into the air filter intake pipe, turbocharger compressor, etc. For instance. if you are finding oil accumulation stuck in the intercooler, this catch can is a necessity. Oil coating the inside of the intercooler will lower the thermal efficiency of the intercooler.