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. This oil catch can kit is compatible with all BMW 135i, 335i, and 535i models with the 3.0L twin turbo N54 engine. An oil catch can is essential on a performance vehicle to protect the engine from elevated levels of crankcase blow-by accumulated from aggressive driving. Excess oil saturated air circulating back into the air intake stream can lead to degraded performance. Radium Engineering's closed loop system does NOT vent to atmosphere (VTA), thus is emissions and track legal. Instead, clean filtered air routes back in through the engine to be burned and to promote negative crankcase pressure for optimal performance. Furthermore, a closed system prevents unwanted oil vapors entering into the cabin.  The kit secures to the OEM power steering reservoir mount with no cutting or drilling required. Includes-Aluminum oil catch can with integrated dipstick-Aluminum laser cut BMW specific mounting bracket-Aluminum 10AN BMW specific PCV adapter fittings -Aluminum 10AN hose ends and adapter fittings-Enough 10AN PCV hose to work with modified vehicles-Stainless Mounting hardware Features-Effectively raises the octane and increased engine performance from cleaner inlet air-Prevents oil buildup in the intake or intercooler system walls, throttle body, intake manifold, etc.-Excessive oil collection can be an indicator of a damaged engine.-Lowers hydrocarbon emissions-Capacity: 7 fluid ounces-Height (without fittings): 5 inches-Outside Diameter: 2.45 inches The stainless steel filtration media is cleanable and reuseable  Instruction PDF