Radium Engineering catch cans feature large 10AN ORB ports, a 4AN ORB drain port, 2-step oil separation baffling, and an O-ring sealed dipstick. These kits mount using factory holes and integrate perfectly with the surrounding components. They do NOT vent to atmosphere (VTA), thus are emissions and track legal. Closed loop systems remove the oil and sludge from the PCV gasses before it is routed to the engine to be burned. A closed loop system also promotes negative crankcase pressure for optimal performance. Furthermore, closed systems prevent unwanted oil vapors from entering the cabin. The dipsticks built into the catch cans allow easy inspection of accumulated fluid. No cutting, drilling or permanent modifications are required. 20-0729-FL DUAL CATCH CAN KIT, NISSAN V35, VQ35DE/HRCOMPATIBILITY Nissan Skyline (V35), excluding VQ35HR Infiniti G35 (V35), excluding VQ35HR The dual catch can consists of a PCV and a CCV catch can. The dual catch can bracket mounts in the front LH portion of the engine bay and is NOT compatible with the factory air box. The PCV catch can runs inline between the PCV valve and the intake pipe. When the intake manifold pressure is close to or greater than atmospheric pressure, the PCV "check" valves close and, thus, this hoses experience no flow. Conversely, the PCV hoses 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: No inline check valve is required since Radium catch cans are pressure sealed. This means a direct intake manifold connection is permitted. The CCV catch can runs inline between the crankcase vent (CCV) port and the intake pipe. At low loads, it experiences atmospheric pressure. However, when the engine is at high load (WOT), the line will experience high flow from the crankcase into the intake system. This would normally lead to oil and sludge accumulation in the air filter intake pipe. The CCV catch can captures this and promotes clean filtered air back into the intake. INCLUDES-Baffled oil catch can (x 2)-Nissan specific mounting bracket-AN adapter fittings and hose ends-Stainless steel hardware-Radium PCV hose Instruction PDF